摘要
本文分析了轴承钢现有各种强韧化工艺,和细晶、细化碳化物、净化晶界强韧复相等强韧化工艺的优点,研究了几种新的复合热处理工艺、组织与性能。其中最佳的工艺在等硬度下可分别提高 GCr15钢性能（%）;σbb27;aK 66;KIC72;f 100。这是由于在复合热处理中,消除了成分偏聚,细化组织（M,C）,净化晶界,从而避免早期沿晶脆断,充分发挥各种强韧化因素作用,其中以基体组织细化和未溶碳化物细化强韧化起主导作用。
This paper is an attempt to optimize in various heat treatmentprocesses and incorporate the merite of multiple treatment for strengtheningand toughening by grain size and carbide refinements,grain boundary purifi-cation,strong phase and tough phase combination.Some new heat treatmentprocesses have been designed,the corresponing structure and properties havebeen determined,and the mechanism of multiple treatment for strengtheningand toughening has been studied.The best one of the new processes can increase the following mechanicalproperties under same hardness of GCr15 steel by(%):σ_(bb)27,a_k 66,K_(Ic)72 and f 100.It has been discussed theoretically on the basis of experimentalresults and interperted by that,during the phase-transformation in compoundheat treatment,the composition segregation inhibitation,structure refinement(martensite,carbide) and grain boundary purification lead to advoid earlyintergranular fracture and so various strengthening and toughening factors arebrought into fully play,in which the matrix-structure mariensite refinementand the undisolved coarse carbides refinement play an important role in theachievement of strength and toughness.
关键词
轴承钢
复合热处理
强韧化
bearing steel
strengthening and toughening
compound heat treatment
