Effect of Cryogenic Treatment and Carbide Spray Coating on the Wear Behavior of Carburized Steel
This study is to investigate the wear behavior of carburized JIS SNCM 415 Ni-Cr-Mo steel being cryotreated and followed by carbide spray coating for achieving improvement in wear resistance. Comparative specimens of JIS SNCM 439 steel were quenched and tempered to 45HRC to obtain a similar surface condition as the carburized JIS SNCM415 samples. The thickness of WC/Co coatings of 125 μm was deposited with the use of high velocity oxy-fuel (HVOF) process. The microhardness of the WC/Co coatings has been found to achieve 1025±75 HV. A series of wear tests have been carried out on steel samples subjected to various conditions under 95.9N with 180 rpm on a dry block-on-roller tester. From the result of 12 hr wear tests, the mass loss of carburized SNCM 415 steel through cryotreatment was 0.025 g improved from 0.05g of steel without cryotreatment. In addition, the mass loss of carburized SNCM 415 specimen under cryotreatment and HVOF process was further decreased from 0.025 g to 0.002 g. The mass loss of comparative JIS SNCM 439 steel coated by the HVOF process was decreased to 0.002 g from 0.045 g of steel without coating. The results clearly establish that cryotreatment and HVOF process significantly improve the surface hardness and wear resistance of carburized JIS SNCM 415 steel.
Zhengyi Jiang, Xianghua Liu and Jinglong Bu
L. H. Chiu et al., "Effect of Cryogenic Treatment and Carbide Spray Coating on the Wear Behavior of Carburized Steel", Advanced Materials Research, Vols. 154-155, pp. 1143-1151, 2011