Causes of and Mitigation Strategies for Quench Cracking During Heat Treatment

Heat treatment is an incredibly useful step in the manufacturing process for a wide variety of industries and applications. It can be used to make materials softer and easier to fabricate, stronger, tougher, more wear resistant, or some special combination of these. However, there are some risks associated with the heat treatment process. In order to make many materials stronger and harder they must be rapidly cooled from high temperatures, also called quenching. Two of the biggest risks during heat treatment are distortion and cracking, which are most likely to occur during this quenching step.

Distortion and cracking are generally paired together when discussing negative outcomes from heat treatment. This is because the strain that occurs when a material distorts will cause a corresponding increase in stress. When this increase in stress exceeds the ultimate tensile strength of the material, cracking occurs.

However, over time, methods for reducing the risk of distortion and cracking during heat treatment have been developed. Considering the hardenability of alloys, part geometries, and specifics of the heat treatment process, we can use our knowledge and best practices to catch problems before they occur and minimize their effects.