Structural changes of austenitic steel obtained by 532 nm and 1064 nm Nd:YAG laser radiation

Optimum transfer of laser energy to steel surface ensures characteristic changes of austenitic steel to obtain better performance of the work piece whenever it is submitted to wear and/or high temperature or corrosive media. Laser surface hardening through surface melting is done using a focused or near focused beam. Using this procedure one can obtain fine homogeneous structures due to the rapid solidification rates, little thermal penetration, resulting in little distortion, smooth surfaces, reducing work after processing, process flexibility due to possibilities in automation. In the present work, surface hardening with 532 nm and 1064 nm from Nd:YAG pulsed lasers was done to alter surface features of stainless steel samples. Microstructure characterization was carried out by optical and electronic microscopy. Phase transformation during rapid solidification is analyzed and discussed.