Nitrogen as austenite stabilizer

In the weld metal, nitrogen is an austenite stabilizer. It keeps the structure austenitic and thus prevents transformation to martensite. Too much nitrogen makes the weld metal hard and brittle, and the structure becomes susceptible to cracking. Too little nitrogen reduces strength. When welding high-alloy steels, you must therefore pay attention to the nitrogen content, choose the appropriate filler material, and control the cooling so that the structure remains stable.