Epsilon carbide precipitation

Epsilon carbide is a transition carbide that forms during tempering of martensitic steels. It is an intermediate stage that transforms into more stable carbides upon further tempering. During welding, rapid precipitation can make the weld harder and more brittle, increasing the risk of cracking. Therefore, it is important not to cool too quickly in the critical range and to temper the component deliberately after welding if necessary. This way you get the microstructure transformation under control and avoid hard, crack-prone zones.