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.