微观组织对X70管线钢浆料磨损特性的影响

Effects of microstructures on the slurry wear properties of X70 pipeline steels

利用湿砂橡胶轮磨损试验机对同成分不同组织的三种管线钢进行了浆料磨损实验,随后对磨损后的试样表面进行扫描电镜观察和三维白光干涉分析,研究组织类型影响耐磨性的原因及磨损的微观机理.结果表明:当磨损机理以微观犁沟和微观疲劳为主时,复相组织中共存的两相硬度差别越大,磨痕的微观变形越不易协调,磨损质量损失越明显;当整体力学性能接近时,粒状贝氏体+针状铁素体的复相组织最为耐磨,粒状贝氏体+多边形铁素体复相组织次之,板条贝氏体+多边形铁素体复相组织耐磨性最差.

Slurry wear tests of three designed pipeline steels with the same chemical composition but different microstructures were performed by utilizing a wet sand/rubber wheel abrasion test apparatus. The worn surfaces were further investigated by scanning elec- tron microscopy and 3D white light interference analysis to reveal the wear mechanism and the relation between the microstructure and wear resisting perforumnce. It is found that the mass loss increases with the increase of the micro-hardness difference between two pha- ses in the muhiphase strueture when the predominant wear mechanism is micro-ploughing combined with micro-fatigue. That is due to a misfit of micro deformation between the hard phase and the soft phase. Among the three different muhiphase steels with nearly the same mechanical properties, the wear resistance of the granular bainite-acicular ferrite muhiphase structure is the best, followed by the granular bainite-polygonal ferrite structure, and then the lath bainite-polygonal ferrite structure.