残余奥氏体对高铬白口铸铁磨料磨损特性的影响

本文通过改变高铬白口铸铁(15Cr-2Mo-1Cu)的热处理工艺,得到一系列残余奥氏体数量在0～60％范围内变化的基体组织;考察了残余奥氏体对低应力、高应力和有冲击载荷存在的动载磨料磨损特性的影响;运用X射线新方法测定了各种磨损后残余奥氏体诱发马氏体转变的数量、层深及分布梯度.研究结果表明:残余奥氏体对耐磨性的影响与磨损系统和残余奥氏体的稳定性有关.

EFFECT OF RETAINED AUSTENITE ON THE ABRASION WEAR RESISTANCE OF HIGH-Cr WHITE CAST IRON

Abrasive wear tests on high-Cr white cast iron (15Cr-2Mo-1Cu) were carried out using the wet rubber wheel test, the pin-disc tests on garnet and SiC commercial abrasive papers, and abrasive wear under repeated impacts. The microstructure of the iron was changed by varying heat treatment to obtain a range of 0-60% retained austenite in the matrix, while the volume of carbide was kept constant. During abrasion, retained austenite may undergo stress-induced or thermally induced transformation and alter the stress distribution. A. new X-ray technique was developed for measuring the gradient distribution of retained austenite in textured alloys and was successfully applied to white cast iron to measure the gradient distribution of retained austenite after abrasion. It has been shown that the effect of retained austenite on the abrasive wear resistance strongly depends on the wear system and the stability of the austenite, which is related to the gradient distribution of retained austenite after abrasion.