轧辊用高钒高速钢的滚-滑动磨损性能及失效行为研究

Rolling/sliding Wear Property and Failure Behavior of High-vanadium High-speed Steel for Rolls

在高应力滚-滑动(滑动率约10%)条件下,利用自制的磨损试验机研究了高钒高速钢的磨损性能,并利用电子显微镜分析了失效行为.结果表明:高钒高速钢的相对耐磨性是高铬铸铁(Cr20)的2倍以上.磨损失效形式为显微切削与疲劳剥落的复合,兼有碳化物碎裂.碳化物对磨损失效有重要作用,高铬铸铁中的杆状M7C3型碳化物易于弯曲、碎裂而在其内部形成大量裂纹,促进磨损表面产生大块的疲劳剥落;高钒高速钢中团块状VC硬度高、形态好、具有精细亚结构、不易碎裂,可有效地抵御显微切削和疲劳剥落,是高钒高速钢耐磨性优良的原因.

Under rolling/sliding condition （with slip ratio of about 10% ）, the wear property of high- vanadium high -speed steel （HVHSS） was studied via wear testing machine developed by authors, and the failure behavior was analyzed via electron microscope. Results show the relative wear resistance of HVHSS is twice higher than that of high - chromium cast iron （Cr20）. The wear failure is mainly caused by the combined action of micro - cutting and fatigue desquamation, with fragmentation of carbides. Carbides play a important role in affecting wear failure. It is easy for rod shaped M7C3 to bend and crush, and therefor large amount of cracks form in MTC3. This contributes to large lumpy desquamation on worn surface. On the other hand, it is difficult for lumpy VC to crush, so crack can hardly traverse VC and can only bypass it, therefore, VC can play a positive role in slowing down the propagation of crack. The excellent wear resistance of HVHSS is mainly related that VC can efficiently resist mico -cutting and fatigue desquamation because it have high microhardness, good morphology and fine substructure, and well capacity resisting to be crushed.