Improvement of Wear Resistance of Stainless Steel AISI 304L by Diode Laser Surface Alloying with Chromium Carbide

摘要

Metal matrix composite layers have been fabricated on AISI 304L substrate by diode laser surface alloying with direct injection of chromium carbide (Cr_3C_2) powder into the molten-pool. The influence of laser alloying parameters on the quality of the alloyed layers has been investigated. The alloyed layers have been examined by optical metallography and scanning electron microscopy. Comparative erosion tests between the AISI 304L substrate and the alloyed layers have been performed following the ASTM G 76 standard test method. The uniform laser beam intensity profile of the laser used ensures to produce fully dense alloying layers with homogenous distribution of Cr_3C_2 particles throughout the matrix alloy. Distribution and dissolution of Cr_3C_2 particles are strongly dependent on the laser power level. The alloyed layers exhibited noticeable increased erosion resistance in comparison to the AISI 304L substrate for both 30° and 90° impact angles.