50KhFA STEELS BY FRICTION HARDENING

In this work the change in phase composition of the white layers formed by friction- hardening treatment of 40Kh and 50KhFA stels was investigated by the method of layer-by- layer phase analysis (3). The 40Kh steel contained 0.44Z C, 0.06Z Mn, and 1.0Z Cr, and the 50KhFA steel, with a higher carbon content (0.48~), was additionally alloyed with 0.3Z vanad- ium. Special attention was devoted to the electrochemical isolation of the carbides with the use of an aqueous electrolyte of 75 g KCI + 20 g of citric acid in 1 dm 3 H20 at 0~ with a current density of 2 ~A/m 2. The phases were differentiated by a solution of hydrochloric acid in water in a ratio from I:i to 1:4 depending upon the dispersion of the carbides.