Big equipment often requires special processing equipment. Those 300-ton locomotives used unique heat treatment on the gears which required the des...

The most important consideration in deciding whether to rework or scrap and re-make a nonconforming part is functionality. Can the part be made to ...

Suppliers are working hard to make sure their heat treating equipment is controllable, repeatable and efficient, and manufacturers continue to incorporate technology that gives heat treaters and their customers more information about what's going on inside the magic box.

[starbox] In my last posting I wrote about some of the projects I have been involved with to squeeze a bigger part in an existing machine. Most ...

Precision components (industrial bearing races and automotive gears) can distort during heat treatment due to effects of free or unconstrained oil quenching. However, press quenching can be used to minimize these effects. This quenching method achieves the relatively stringent geometrical requirements stipulated by industrial manufacturing specifications. As performed on a wide variety of steel alloys, this specialized quenching technique is presented here, along with a case study showing the effects of prior thermal history on the distortion that is generated during press quenching.

Induction hardening is widely used in both the automotive and aerospace gear industries to minimize heat treat distortion and obtain favorable compressive residual stresses for improved fatigue performance. The heating process during induction hardening has a significant effect on the quality of the heat-treated parts. However, the quenching process often receives less attention even though it is equally important.

The October 2011 issue of Gear Technology featured the article “Low-Distortion Heat Treatment of Transmission Components,” which covered the combination of low-pressure carburizing and high pressure gas quenching in an automotive environment. Here, heat treating expert Dan Herring explains why oil quenching is an appropriate choice for many applications.

This paper presents how low pressure carburizing and high pressure gas quenching processes are successfully applied on internal ring gears for a six-speed automatic transmission. The specific challenge in the heat treat process was to reduce distortion in such a way that subsequent machining operations are entirely eliminated.