What is the technological difference between Case Hardening and Induction Hardening?

Two methods have become established for Induction hardening work pieces in mass production: case hardening and induction hardening. A comparison of these two methods shows their differences and the advantages of each.

Case Hardening vs. Induction Hardening – a Comparison

If one compares the two methods for hardening steel work pieces (for a general explanation of hardening see here: Hardening), then the first striking difference is the parts handling. While case hardening processes a large number of work pieces at the same time, induction hardening focuses on the individual work piece. With induction hardening, components are hardened work piece by work piece. For case hardening, “batch by batch” would be a better description.

Of courses, this has an impact on the manufacturing. While case hardening relies on parts logistics to carry parts between the production line and hardening, induction hardening can be integrated directly in the production line with a suitable hardening machine (e.g. MIND series) and be part of the cycle.

Case hardening in detail

As mentioned above, case hardening is done in batches. As with induction hardening, the goal is to harden the outer layer of work pieces. 

In case hardening the work pieces are hardened by carburization. The steel is heated to over 880 °C to become austenitic. Then coal is transferred into the part from a CO-emitting medium through the part’s surface. The diffusion causes the edge of the work piece to receive more carbon, while the carbon density remains the same toward the center. 

Hardening occurs after the application of carbon. Penetration of carbon is critical for the hardness and the depth hardness characteristic of the work piece. The hardening, i.e. the hardness and the hardening depth, is defined by the carbonization depth, the receptiveness and thus the harden ability of the steel, and the quenching. The more carbon is inside an area of the work piece, the more successful the hardening in that area. 

After hardening, the work pieces are annealed (for more information about annealing please see here: Annealing) to restore some of their plasticity. The goal of any hardening process is to make the edge resistant to mechanical loads while giving the part enough elasticity to deflect external forces without damage. 

There are two ways to influence the hardening depth in case hardening: One is to manipulate the heating of the work piece, e.g. by application of special pastes that prevent heating in certain places. The other is by influencing the quenching process, e.g. by immersing only certain parts of the work piece.  

With both methods, results are not particularly accurate and reproducible only within a relatively wide tolerance range. This is very different for Air Coolers and Oil Coolers in Faridabad.

Induction hardening in detail

As mentioned above, each part is hardened separately with the induction hardening technology. Each part is heat treated, quenched, and annealed (if necessary) separately.

In addition to integration in the production line, the great advantages of induction hardening are precise control and reproducibility of hardening results. 

To achieve this, the entire hardening process from the inductor and the applied energy and frequency to quenching and annealing is specially adapted to the relevant work piece. This yields excellent hardening results, even for work pieces with complex geometriesen

ing

Which hardening method is the right one?

Which Induction hardening in Faridabad process is suitable for an application depends on several factors. Both methods, case hardening and induction hardening, have advantages and downsides.

For the mass production of components in medium or large quantities however, induction hardening offers a range of benefits:

• With a suitable hardening machine, induction hardening can be fully integrated in the cycle of the production line and automated.
• Especially with induction hardening, results are reproducible, which contributes to a consistently high quality in production.
• This reduces unit costs considerably

Air & Fuel Oil Coolers - Turbine Lubrication System Components

Air Oil Coolers

Two basic types of oil coolers in general use are the air-cooled and the fuel-cooled. Air oil coolers are used in the lubricating systems of some turbine engines to reduce the temperature of the oil to a degree suitable for recirculation through the system. The air-cooled oil cooler is normally installed at the forward end of the engine. It is similar in construction and operation to the air-cooled cooler used on reciprocating engines. An air oil cooler is usually included in a dry-sump oil system. This cooler may be air-cooled or fuel-cooled and many engines use both. Dry- sump lubrication systems require coolers for several reasons. First, air cooling of bearings by using compressor bleed-air is not sufficient to cool the turbine bearing cavities because of the heat present in area of the turbine bearings. Second, the large turbofan engines normally require a greater number of bearings, which means that more heat is transferred to the oil. Consequently, the oil coolers are the only means of dissipating the oil heat and Induction Hardening Faridabad.

Fuel Oil Coolers

Induction Hardening Faridabad and the fuel-cooled oil cooler acts as a fuel oil heat exchanger in that the fuel cools the hot oil and the oil heats the fuel for combustion. Fuel flowing to the engine must pass through the heat exchanger; however, there is a thermostatic valve that controls the oil flow, and the oil may bypass the cooler if no cooling is needed. The fuel/oil heat exchanger consists of a series of joined tubes with an inlet and outlet port. The oil enters the inlet port, moves around the fuel tubes, and goes out the oil outlet port.

Induction hardening offers excellent hardness distribution with minimal defects

Induction hardening offers significant advantages over traditional methods for heat-treating steel, alloy, and other metal parts. This process is perfect for metal with a carbon content of more than 0.3%, particularly hardened steel with a low alloy content (C34, C35, C60, etc.), as described in the DIN EN 100083 industry norm. Shafts, gears, armatures, sprockets and other components can all be hardened using this induction process.

The process is very demanding on the equipment and the inductor used. Ideal hardening results can only be achieved by perfectly matching a precisely controlled energy source with an optimum inductor design. eldec's experienced engineers custom design the induction coils to meet customer unique specifications, including single turn, two-turn, face-heating, clamshell, and clamp inductors. Every machine is completely inspected and tested to ensure optimum power and heat settings.

Heating directly with induction hardening

Induction hardening in Faridabad is a process in which the heat is generated directly in the work piece. The principal advantage of this type of heat treatment is that the material quickly reaches the desired temperature to produce hardened metal parts. With traditional heat treatments such as flames, ovens, or by convection, heat is applied to the part by heating up the surface layer. These methods take considerably longer and require significantly more energy to produce the desired hardness. Induction hardening, by contrast, offers extremely short heating times. It is a very effective and attractive method in the manufacturing of steel shafts, components, and other metal parts across a range of industries. Additionally, induction heating can be very precisely controlled via the power, frequency, and inductor geometry. This minimizes deformities in the workpiece and ensures the efficiency of the process.

How induction hardening works

The primary application of this induction method is the hardening of steel. One or many induction coils are used to generate and target an alternating magnetic field. This magnetic field produces eddy currents in the metal, which heat the workpiece up to the desired temperature. Immediately after heating, the component then goes through a quenching process using water, oil, or an emulsion. This cools the metal until martensitic transformation occurs, producing a hardened surface that is tougher than the base metal.

After quenching, the steel undergoes tempering, a low-temperature heat treatment process, to reach the desired hardness / toughness ratio. The maximum hardness of a steel grade obtained through the hardening process gives the material a low toughness. Treating the steel through tempering reduces the hardness in the material and increases its toughness.

The hardening depth in the work piece is controlled, very precisely, by adjusting the electrical power output of the induction machine and the frequency of the inductor / coil current. The thickness of the heated layer from the surface of the metal to some point below the surface is inversely proportional to the frequency of the applied alternating current. Higher frequencies produce thinner skins. Case hardening in Faridabad the surface of steel increases the wear resistance of the component without reducing the ductility of the bulk of the material. eldec offers energy sources with the latest converter technology in three frequency ranges:

• Low: 1 – 7 kHz
• Medium: 8 – 40 kHz
• High: 60 – 500 kHz

Induction hardening with SDF

With Simultaneous Dual Frequency, also known as SDF, eldec offers an additional method that is used especially for work pieces with complex shapes. A medium frequency is overlaid with a high one so that both act upon the material simultaneously at a uniform depth. This guarantees the component is heated at a consistent temperature across the entire part to ensure even surface hardness. This application is perfect for the process of manufacturing cogs and gears. Even though the top and bottom of the gear teeth are at different distances from the inductor, a smooth and precise hardness layer can be achieved.

Induction Hardening of Steering Pinions: High-Speed Process – High Component Quality

The standardization of production is a trend in automotive engineering as uniformly designed; perfectly configured production plans guarantee highly efficient practices at different sites. The production process is tailored to different components – a trend which naturally also affects mechanical engineering, since “off-the-rack” solutions cannot meet this demand. The example of the induction hardening of steering pinions clearly shows the system concepts machine manufacturers are developing to react to this Induction Hardening in Faridabad offers customized systems to integrate hardening into the production flow.

Millions of steering pinions are produced every year by large supply companies. This component is used in all steering systems and ensures that the steering force is transferred to the steering gear and then ultimately to the wheels – a process that happens millions of times over the life cycle of a car. This means that the strength of these components, and the material used to produce them, has the very highest priority, making hardening processes essential. However, hardening components produced in large scale manufacturing processes often presents a logistical challenge. Many suppliers have the process completed by a third party in the form of case hardening, requiring a heat treatment specialist, creating additional costs and planning work.  

Hardening in less than one second

Inductwell.com delivers a whole host of benefits in this respect. This is a global player with headquarters and develops, manufactures and sells highly efficient induction heating technology for a very wide range of industrial applications. The technological alternative to case hardening is not only faster and more energy efficient, but Induction Hardening can be integrated perfectly in series production systems where they become integral components of complete production lines. Making this a viable option is the speed of the process. While a steering pinion must be heated over a period of hours for case hardening, the induction process takes less than one second with the heat applied by the induction of eddy currents.

SDF technology improves component quality

The benefits of a special Inductwell.com innovation are particularly clear when processing steering pinions – generators featuring simultaneous dual frequency (SDF) which supply the energy for the hardening machines. With SDF, two different frequencies are applied to the work piece. While mid-frequencies generally penetrate more deeply and, above all, heat the foot of the tooth, high frequencies heat the head of the tooth. The heating process on the steering pinion using SDF therefore achieves absolutely uniform depth and temperature levels. This ensures a standard hardening finish even on large modules. “We tailor the required energy source perfectly to the component. There are no standard solutions.

Hardening technology from a single source

The same also applies to the eldec module induction (MIND) series of hardening machines, also perfectly tailored to the work piece dimensions, required hardening finish and batch size. Only time-tested components are used thanks to the company’s modular element system. This benefits the stability of the systems and also means that the technology offers proven value for the investment. Finally, made with micrometer precision based on the work piece using 3-D CAD software, the production of the inductor tools also meets the customer’s specifications. “We supply our customers with a tailored machine which includes robot automation systems, if necessary. They can be integrated perfectly in production lines with soft and subsequent hard machining processes as a complete hardening system,” explains Rechtacek.  Steering pinion production from the raw part to the finished component can then be carried out in a multi-stage process which may also feature grinding and turning machines from EMAG. Automotive customers are supplied with a complete turnkey solution.

Focusing on machining quality 

Finally, the guaranteed machining quality and true to size properties of the MIND Series lends it to the large scale production of this safety-relevant component. The expansion of the steering pinion using Induction hardening job work technology is a maximum of just 0.2 millimeters. This is an extremely low value for hardening, and one which can be reproduced at any time – a major factor for the establishment of new production plants in Asia or South America. “We are often approached by companies that require extraordinary machining quality for their components. We can guarantee that reproducibility. We also supply custom systems for extremely low cost hardening processes. These benefits mean that we are enjoying ever greater success on the market,” concludes Rechtacek. 

Case hardening with subsequent hardening operation

Case hardening process used to increase wear resistance, surface hardness and fatigue life through creation of a hardened surface layer while maintaining an unaffected core micro structure.

Induction hardening in Faridabad is used to increase the mechanical properties of ferrous components in a specific area. Typical applications are power train, suspension, engine components and stampings. Induction hardening is excellent at repairing warranty claims / field failures. The primary benefits are improvements in strength, fatigue and wear resistance in a localized area without having to redesign the component.

Benefits

Induction imparts a high surface hardness with a deep case capable of handling extremely high loads. Fatigue strength is increased by the development of a soft core surrounded by an extremely tough outer layer. These properties are desirable for parts that experience tensional loading and surfaces that experience impact forces. Induction processing is performed one part at a time allowing for very predictable dimensional movement from part to part.

Application & materials

Induction hardening is a heat treatment process carried out to enhance the mechanical properties in a localized area of a ferrous component. The resultant hardened area improves the wear and fatigue resistances along with strength characteristics.

Typical applications of induction hardening include gears, shafts, axles, cam lobes, and stampings, and spindles, mostly symmetrical parts. Induction hardening is used to strengthen a specific area of a part.

Single piece, surface hardening of selective areas

·         Carbon steels

·         Alloy steels

·         Stainless steels (martensitic)

·         Powder metal

·         Cast iron

·         Gray iron

·         Ductile iron

·         Malleable iron

Process details

Induction hardening is a process used for the surface hardening of steel and other alloy components. The parts to be heat treated are placed inside a copper coil and then heated above their transformation temperature by applying an alternating current to the coil. The alternating current in the coil induces an alternating magnetic field within the work piece which causes the outer surface of the part to heat to a temperature above the transformation range.

The components are heated by means of an alternating magnetic field to a temperature within or above the transformation range followed by immediate quenching. It is an electromagnetic process using a copper inductor coil, which is fed a current at a specific frequency and power level case hardening in Faridabad.

Special issue published: "Induction Heating and Heat Treating"

• Estimation of the heat flux density during the Induction Hardening in Faridabad process based on the parametric optimisation
• Simulation and optimisation of heating stages in a new resource efficient forging process chain
• Investigation of the intermediate layers formed by austenitic nitrocarburising
• Numerical analysis of computational models for induction heat treatment of complex geometrical parts
• Metallurgical and mechanical implications of inductor and process design factors in induction heat treatment
• Influence of diode laser surface melting on microstructure and corrosion resistance of 7075 aluminium alloy
• Electromagnetic forming analysis of AA5182 at elevated temperatures
• Elimination of straightening operation in Induction Hardening of automotive camshafts

Induction Hardening Provides Many Benefits!

Increased surface hardness, strength and wear resistance

The increased hardness is due to martensitic transformation, which is achieved in a selected area of the part by heating with an induction coil followed by a rapid (water + polymer) quench Induction hardening.

Increased strength and fatigue life due to the soft core and residual compressive stress at the surface

This is a result of the hardened structure near the surface occupying slightly more volume than the core.

Parts may be tempered after induction hardening to adjust hardness level as desired

As with any process which produces a martensitic structure, tempering will lower hardness while decreasing brittleness.

Deep case with tough core

We can harden to case depths of up to .45” while maintaining a soft core.  Yes that’s .45”, nearly a half inch!  While case depths of .030” - .100” are more typical, deeper case depths are achievable with the right material.  A deep case is appropriate for larger parts under high stress, or parts which are still useful even after much material has worn away.

Selective hardening process with no masking required, areas with post-welding or post-machining stay soft

Very few other heat treat processes are able to achieve this.

Relatively minimal distortion

Imagine a shaft 1” Ø x 40” long, which has two evenly spaced journals; each 2” long requiring support of a load and wear resistance.  Ultra Glow induction hardening is performed on just these surfaces, a total of 4” length.  With a conventional method (or if we induction hardened the entire length for that matter), there would be significantly more war page case hardening in Faridabad.

Allows use of low cost steels such as 1045

The most popular steel utilized for parts to be induction hardened is 1045.  It is readily machine able, low cost, and due to a carbon content of 0.45% nominal, it may be induction hardened to 58 HRC +.  It also has a relatively low risk of cracking during treatment.  Other popular materials for this process are 1141/1144, 4140, 4340, ETD150, and various cast irons.  Lower carbon steels can be induction hardened as well, although naturally the maximum hardness achieved will be lower.  For example, 4130 will reach 50 HRC+ and is much safer on parts prone to cracking during hardening. 

On production runs of medium to larger parts, induction hardening is frequently less expensive than other heat treatments:

• It takes a less energy to heat just the area requiring hardening, rather than the entire part.
• Quenching is fast due to the water based quench and the reduction in heat removed oil coolers in Faridabad.
• Tempering is not required as frequently as it is with conventional heat treat.
• An atmosphere is not used, saving utility costs.
• There is no labor or material cost for masking.

Benefits of Induction Hardening

Induction hardening is a form of heat treatment in which a metal part is heated by induction heating and then quenched. The quenched metal undergoes a marten’s tic transformation, increasing the hardness and brittleness of the part. Induction hardening is used to selectively harden areas of a part or assembly without affecting the properties of the part as a whole.

Process

Induction heating is a non contact heating process which utilizes the principle of electromagnetic induction to produce heat inside the surface layer of a work-piece. By placing a conductive material into a strong alternating magnetic field, electric current can be made to flow in the material thereby creating heat due to the I2R losses in the material. In magnetic materials, further heat is generated below the Curie point due to hysteresis losses. The current generated flows predominantly in the surface layer, the depth of this layer being dictated by the frequency of the alternating field, the surface power density, the permeability of the material, the heat time and the diameter of the bar or material thickness. By quenching this heated layer in water, oil, or a polymer based quench, the surface layer is altered to form a marten’s tic structure which is harder than the base metal.

Definition

A widely used process for the surface hardening of steel Induction hardening. The components are heated by means of an alternating magnetic field to a temperature within or above the transformation range followed by immediate quenching. The core of the component remains unaffected by the treatment and its physical properties are those of the bar from which it was machined, whilst the hardness of the case can be within the range 37/58 HRC. Carbon and alloy steels with equivalent carbon content in the range 0.40/0.45% are most suitable for this process.

A source of high frequency electricity is used to drive a large alternating current through a coil. The passage of current through this coil generates a very intense and rapidly changing magnetic field in the space within the work coil. The work piece to be heated is placed within this intense alternating magnetic field where eddy currents are generated within the work piece and resistance leads to Joule heating of the metal.

This operation is most commonly used in steel alloys. Many mechanical parts, such as shafts, gears, and springs, are subjected to surface treatments, before the delivering, in order to improve wear behavior. The effectiveness of these treatments depends both on surface materials properties modification and on the introduction of residual stress. Among these treatments, induction hardening is one of the most widely employed to improve component durability. It determines in the work-piece a tough core with tensile residual stresses and a hard surface layer with compression stress, which have proved to be very effective in extending the component fatigue life and wear resistance.

Induction surface hardened low alloyed medium carbon steels are widely used for critical automotive and machine applications which require high wear resistance. Wear resistance behavior of induction hardened parts depend on hardening depth and the magnitude and distribution of residual compression stress in the surface layer of Induction hardening Faridabad.

Induction Heating

Inductors are very efficient: very little energy leaks out of the pot into the air - most of it is transmitted into the kettle, which heats the water. In contrast, conventional hobs just get hot: they heat the kettle, because it's nearby, but lots of energy also escapes into the air. So, an induction cooker is very fast at heating water, compared to Induction hardening Faridabad.

We can see that the ceramic hot-plate isn't there to heat the kettle, because that's being performed by the field - in fact, it's there's to insulate the fairly delicate induction circuitry from the hot kettle. To stop it overheating, it needs to be cooled from underneath, and so tea-versions usually have a noisy fan roaring away. I don't like this about induction cookers. It really ruins the tea atmosphere.

Induction also has lots of other fun applications: as the water heats, the characteristics of the field change, which can be sensed by the induction unit, and so the field can be changed to compensate. This allegedly leads to induction kettles with temperature control - but they're usually fairly horrible. I've not seen one that I could trust so far, and it's infinitely easier (and more reliable) just to learn it yourself - and more satisfying in oil coolers in Faridabad.

Induction also requires some resilient materials. The magnetic field is always set up in the same way, and the location of the most heated areas is concentrated spatially - it's not an "all over" heat, like a conventional hot-plate would provide, but appears in regular "hot spots". You're heating the base of your vessel in a fixed pattern, repeatedly, and the (really rather significant) temperature differential across the metallic lattice can lead to stress fractures. Don't put your expensive Japanese kettle on an induction hob Induction hardening Faridabad!

Indirect Cooling - Induction Hardening Faridabad

Air cooled engines, like the one in my airplane, are actually cooled by more than just air blowing past the cylinder's cooling fins.  Internally, some of the heat is carried away by the engine oil.  This cooling is improved by the addition of a radiator for the oil.  In this posting, I will illustrate the installation of my oil cooler Induction hardening Faridabad.

The engine in my plane is a little larger than the standard engine for this aircraft and so I elected to go with a larger oil cooling radiator.  The trouble is that the larger radiator will not fit in the standard location which is hanging off of the baffles behind the rear left cylinder.  To overcome this problem, I will be relocating the cooler to the left side fire wall.

Whenever you veer off of the plans to make some sort of modification to the stock aircraft you are skating on ever thinner ice as you go.  But this mod doesn't have any structural ramifications so I think I'm pretty safe here.

First up:  make some brackets to mount the cooler to the firewall.

The cooler's air source will be the higher pressure air above the engine on the left side and will be connected to the cooler by a flexible 4" hose.  An intake plenum is required to adapt the hose to the cooler and that will be constructed of fiberglass.  A male mold is fashioned using modeling clay and a roll of tape that is just the right size for the hose (after I peeled off about 5 ft of tape) case hardening in Faridabad.

Indirect Cooling

In indirect cooling, the oil is cooled through the heat transfer of an intermediate medium, Weber explained.

“This is an outside system with an external heat exchanger, which uses water, liquid [such as glycol] or refrigerant, or thermos phoning to cool.” Shell-and-tube and plate-type heat exchangers would both use indirect coolers.

In water-cooled external heat exchangers, oil flows out of the separator. Either a pump or differential pressure forces oil through the heat exchanger. The oil temperature usually is controlled by the thermostatic valve controlling bypass of the heat exchanger.

Weber said that water-cooled cooling system components include :

• External shell-and-tube or plate-type heat exchangers;
• Three-way valve for temperature sensing, or a water-regulating valve;
• External piping; and
•  A relief valve
• The heat exchanger cools the oil before it is injected into the compressor.

How Oil Cooler Work and Common Problems?

In a stock setup, transmission fluid is cooled as its collected heat transfers to the colder engine coolant that surrounds it. Coolers usually work best when mounted in front of a stock radiator since this is where it can often get the most unobstructed source of oil coolers in Faridabad. This, in turn, allows much cooler fluid to return back to the transmission case.

While a majority of cars are not manufactured with proprietary engine oil coolers, there is a large aftermarket for them in many places, and they are common accessories in vehicles involved in towing and other heavy-duty applications. People can buy oil cooling kits to upgrade their vehicles themselves, though this usually requires a bit of expertise. Many professional shops will also install these for people looking for ways to make their machines more efficient.

Common Problems

The optimum temperature for oil is usually between 180° and 200°F (82° and 93°C). Failures start to occur when oil cannot dissipate its collected heat fast enough and rises past this threshold, which can begin to degrade the oil. Oil loses its lubricating, as well as its cooling, properties when it starts to break down, and this can lead to a number of serious engine and transmission problems. Induction hardening should usually be inspected fairly regularly to keep them in good working order, and owners should take care to regularly inspect and service them to avoid major failures.

Oil Cooler System

Ø  To prevent the unconstrained heating of the oil, most high-performance hydraulic systems include a hydraulic oil cooler, a device placed in line with the system to allow heat to dissipate from the oil.

Ø  As the mixture grows steadily cooler, other compounds condense, until it hits the top of the column.

Oil Cooler Radiator

Ø  An oil cooler is essentially any device or machine intended to cool oil, but in most instances people talk about it in the context of cars, trucks, and sometimes airplanes.

Ø  The cooling medium absorbs heat from the oil and carries it away from the cooler, where it is typically shed into the atmosphere. Common hydraulic coil cooler designs include radiator, shell and tube, or plate and frame types.

Large Oil Cooler

Ø  While a majority of cars are not manufactured with proprietary engine oil coolers, there is a large aftermarket for them in many places, and they are common accessories in vehicles involved in towing and other heavy-duty applications.

Ø  The lubricating oil in automobile engines also serves as a coolant, thereby absorbing heat from the combustion area and shedding it through separate oil cooler or the reserve oil in the engine sump. Large industrial gearboxes and drive trains also utilize combined oil lubrication and cooling.

Industrial Oil Cooler

Ø  An oil cooler is essentially any device or machine intended to cool oil, but in most instances people talk about it in the context of cars, trucks, and sometimes airplanes.

Ø  The lubricating oil in automobile engines also serves as a coolant, thereby absorbing heat from the combustion area and shedding it through separate oil cooler or the reserve oil in the engine sump. Large industrial gearboxes and drive trains also utilize combined case hardening in Faridabad.

Edition Process of Induction Hardening

Induction hardening Faridabad is a form of heat treatment in which a metal part is heated by induction heating and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part. Induction hardening is used to selectively harden areas of a part or assembly without affecting the properties of the part as a whole.

Process Edit

Induction heating is a non contact heating process which utilizes the principle of electromagnetic induction to produce heat inside the surface layer of a work-piece. By placing a conductive material into a strong alternating magnetic field, electric current can be made to flow in the material thereby creating heat due to the I2R losses in the material. In magnetic materials, further heat is generated below the Curie point due to hysteresis losses. The current generated flows predominantly in the surface layer, the depth of this layer being dictated by the frequency of the alternating field, the surface power density, the permeability of the material, the heat time and the diameter of the bar or material thickness. By quenching this heated layer in water, oil, or a polymer based quench, the surface layer is altered to form a martensitic structure which is harder than the base metal.

Definition Edit

A widely used process of the surface hardening of steel. The components are heated by means of an alternating magnetic field to a temperature within or above the transformation range followed by immediate quenching. The core of the component remains unaffected by the treatment and its physical properties are those of the bar from which it was machined, whilst the hardness of the case can be within the range 37/58 HRC. Carbon and alloy steels with equivalent carbon content in the range 0.40/0.45% are most suitable for this process.

A source of high frequency electricity is used to drive a large alternating current through a coil. The passage of current through this coil generates a very intense and rapidly changing magnetic field in the space within the work coil. The work piece to be heated is placed within this intense alternating magnetic field where eddy currents are generated within the work piece and resistance leads to Joule heating of the metal of oil coolers in Faridabad.

This operation is most commonly used in steel alloys. Many mechanical parts, such as shafts, gears, and springs, are subjected to surface treatments, before the delivering, in order to improve wear behavior. The effectiveness of these treatments depends both on surface materials properties modification and on the introduction of residual stress. Among these treatments, induction hardening is one of the most widely employed to improve component durability. It determines in the work-piece a tough core with tensile residual stresses and a hard surface layer with compressive stress, which have proved to be very effective in extending the component fatigue life and wear resistance.

Induction surface hardened low alloyed medium carbon steels are widely used for critical automotive and machine applications which require high wear resistance. Wear resistance behavior of induction hardened parts depend on hardening depth and the magnitude and distribution of residual compressive stress in the surface layer of Case Hardening in Faridabad.

History Edit

The basis of all induction heating systems was discovered in 1831 by Michael Faraday. Faraday proved that by winding two coils of wire around a common magnetic core it was possible to create a momentary electromotive force in the second winding by switching the electric current in the first winding on and off. He further observed that if the current was kept constant, no EMF was induced in the second winding and that this current flowed in opposite directions subject to whether the current was increasing or decreasing in the circuit.

Faraday concluded that an electric current can be produced by a changing magnetic field. As there was no physical connection.

Comparing Induction Hardening, Case Hardening

What Is Induction Heating?

Induction Hardening relies on the existence of eddy currents discovered by Léon Foucault in 1855. Briefly, when a changing magnetic field passes through any conductive object, current flow is induced in the object. That current flow creates a secondary electric field in the conductor. The secondary electric field, in turn, produces another flow of current which is known as the eddy current, so named because it flows in a circular pattern, much like water can swirl in a slow-moving stream when it encounters an obstacle. The push-pull between these fields—literally, the kinetic energy caused by electrons being shuttled back and forth—produces heat in the conductor.

Induction Heating Applications

Induction heating is used to manufacture end items as diverse as bulldozers, spacecraft, faucets and sealing plastic lids on pharmaceutical bottles. The fundamental design of an induction heating device uses a coil of wire and an AC current to induce a changing magnetic field in the item to be heated—the work piece. The coil can measure only a few centimeters in diameter, or any other dimension suited to the job at hand.

The work piece is placed inside the magnetic field generated by the coil, but not in contact with it, then heated to the desired level by the eddy currents. Depending upon the material being heated, temperatures as high as 2,200° F (1,200° C) can be achieved.

Induction heating is clean, requiring no fossil fuels. Parts exposed to induction heating simply heat up, so there's no cleanup afterward and no worry about contamination of the work piece. It's also fast. For example, manufacturers of pipes and tubular channels use induction heating to weld a seam along the longitudinal dimension of pipes passing by at high speed on a conveyor.

A few other processes that use induction heating include:

• ·      Induction hardening and tempering, which alters the physical characteristics of materials to meet the needs of various applications.
• ·       Induction melting can be used to melt any ferrous or non-ferrous metal, including nuclear material and various alloys used in medicine and dentistry.
• ·     Metal and carbon fiber materials can be bonded together by heating them, thereby curing adhesives placed between two surfaces.
• ·     Soldering, brazing and welding are all natural applications for induction heating where precise temperature control and accurately confining heat to the desired area is important in air cooler oil cooler.

Induction Heating Solves Real Problems

The so-called Tylenol Murders took place in Chicago during 1982 when someone, never identified, laced Tylenol bottles with cyanide. The subsequent events led to a nationwide recall of Tylenol products. The poisoning also forced the entire over-the-counter pharmaceutical industry to package their products in tamper-proof containers.

The aluminum foil that's commonly used to seal OTC drugs is part of the industry's solution, and it uses induction heating. The process begins by placing the foil, which is electrically conductive, into the cap. The cap is screwed down, and then the entire package is placed inside an induction heating coil. As the foil heats up, adhesives around its edge adhere it to the lip of the bottle.

Designers of induction cap sealing equipment must take several factors into account. The induction heater's physical dimensions need to be tailored to the containers to be sealed. The electromagnetic field needs a depth suitable for heating the foil. The heating should take place as quickly as possible for productivity reasons. The efficiency of the induction heater needs to achieve a specific performance level.

These and other design constraints can be reduced dramatically when the wire used to make the coil is custom-manufactured. New England Wire Technology, a long-time supplier to the induction heating market, provides wire specially made to solve such design problems in Induction Hardening Faridabad.

For instance, NEWT can supply round, square and rectangular conductors. Their exact size can be tailored specifically for the AC current and frequency to be used. And, because the efficiency can be optimized in the wire itself, the induction cap sealer design engineer has much greater flexibility in choosing the spacing, shape and size of the sealing head. In fact, that same flexibility benefits designers of any induction heating device.

Case Hardening

Heat-treatment processes such as case hardening are used to prolong the service life by increasing the surface hardness and vibration resistance while maintaining a ductile, elastic microstructure at the core. Steels suitable for case hardening have a carbon content of approximately 0.1-0.3% weight percent. For a high surface hardness – for example, 60 HRC – a carbon content of 0.1-0.3% is not sufficient. The part has to be carburized.

Carburization takes place by diffusion of the carbon into the work piece surface. A mixture of carrier gas and additive gas forms the basis for the carburization atmosphere in the furnace. Crucial factors for the right choice of the carburization process are the material-specific parameters, hardening demands in conjunction with the gas composition and a continuous, homogeneous furnace atmosphere.

Hardening is achieved by heating to austenitizing temperature with a sufficiently long holding time and subsequent quenching process. What is crucial here is that the carbon in the austenite is brought into solution. The amount of carbon is dependent on the material composition and the state of the initial microstructure. Excessive holding times or excessive temperatures during the austenitizing process can have a negative impact on the grain growth and material microstructure.

The hardening process can be followed by a low-temperature cooling process or direct tempering process. Both processes result in a reduction of the residual austenite and of the hardness and distortion properties.

Tempering is performed in different temperature ranges. The tempering temperature of parts made of low-alloy or unalloyed steels generally lie between 180-250°C (356-482°F). A higher temperature leads to a greater drop in hardness.