Abstract:
In order to study the influence of different spheroidizing annealing processes on the carbide of GCr15 bearing steel wire, the quantity, size and microhardness of carbides treated by four different annealing processes were analyzed by means of micro-electron microscopy and optical image processing software. The results show that when the solid solution temperature of annealing pro-cess was 800˚C and heat preservation 1 h with 25˚C/h cooling rate with furnace cooling to 700˚C, after1 h with 15˚C/h cooling rate with furnace cooling to 650˚C, and then air cooling; the particles of carbide are the finest with an average size of 0.23 um and the most rounded. When the solid so-lution temperature is in the range of 780˚C~800˚C, the higher the solid solution temperature, the better the spheroidization effect; the longer the holding time, the finer the carbide particles after annealing. The annealing process has a certain effect on the microhardness of the steel, but to a limited extent.
