Deformation-Induced Phase Transformation

Targeted transformation of metastable microstructural constituents (such as austenite to martensite) driven by mechanical stress, leading to pronounced work hardening and high energy absorption.

Special case: When welding austenitic steel and it is subsequently heavily mechanically stressed, the structure can locally transform into martensite. This makes the spot harder and stronger, but also more brittle and prone to cracking. So watch out if the weld is cold-formed afterwards. The transformation then happens exactly where the most stress is. If you don't want that, you have to keep an eye on heat input and cooling, otherwise you'll end up with a hard, cracked spot.

MetallurgieSchweißtechnik