高炭素高速度鋳鋼の熱処理及びころがり疲労特性 Characteristic of Heat Treatment and Rolling Contact Fatigue of High Speed Cast Steel Containing High Carbon
Fe-1.8 % C-Cr-Mo-W-V-Co alloys varying in 4 % and 7 % of vanadium content, 0 % and 5 % of cobalt content and 5 % of each alloying element (Cr, Mo and W) were produced by casting. The characteristics of heat treatment with these alloys quenched and tempered were investigated and their rolling contact fatigue strength was studied. The quenching temperature at which the highest matrix hardness was obtained for quenched alloys became higher as the vanadium content was increased. Tempering at about 773 K resulted in the secondary hardening of the alloys. The high vanadium alloy, which contained less plate-like or rod-like M<sub>2</sub>C carbides and more granular MC carbides, showed excellent rolling contact fatigue characteristics. Since the interface between the carbides and matrix had many defects, binding force between the carbides and matrix was small and cracks propagated along the defective interface. Cracks also passed through plate-like or rod-like brittle M<sub>2</sub>C carbides which were highly sensitive to notch effects when they intersected the carbides.
- 鋳造工学 = Journal of Japan Foundry Engineering Society
鋳造工学 = Journal of Japan Foundry Engineering Society 71(2), 85-91, 1999-02