软磨粒冲刷下材料的行为及磨损机理

研究了具有不同硬度的材料在不同硬度的磨粒冲刷下的磨损特性。结果表明,在相对较软磨粒冲刷下,即使磨粒硬度低于材料硬度,也能使材料发生磨损。且韧性材料的冲刷磨损率随冲击角的增大而增大。对材料的磨损形貌进行了研究,其软、硬磨粒造成的磨损形貌是不相同的。在低角度下,较软磨粒的冲刷使材料发生犁沟及小片脱落,而不像通常硬磨粒冲刷下材料呈现微切削及锻和挤压。研究了热处理硬化后钢在较软磨粒冲刷下的磨损行为,建立了硬度影响磨损率的规律。在高硬度的磨粒冲刷下(H_p/H_m>3)*,材料的硬度变化对冲刷磨损率影响很小,即以热处理硬化来改善材料抗冲刷磨损作用并不大。而在较软磨粒冲刷下(H_p/H_m<3)材料硬度对冲刷磨损率有影响,热处理强化可提高材料抗冲刷磨损性能。

Behavior and Wear Mechanism of Materials Eroded by Soft Particles

This paper deals with the erosion behavior of materials of various hardess impacted by particles of various hardness.It is found that when impacted by soft particles,erosive wear of materials does occur,even though the hardness of particles is lower than the hardness of materials,and the erosion rate increases with attack angle.This angular dependence,similar to that of erosion of brittle materials is different from that for erosion caused by hard particles which shows the maximum erosion rate at low angle.The topographic features of eroded surface obtained at low incidence angle are studied by SEM.There are great difference between topographies caused by soft particles,which show evidenc of ploughing and platelets detachment,and topographies caused by hard par tides,which are proof of micromachining and forging and extruding.The characteristics ot erosion of heat-treated steels by soft particles are also studied.It is found that,under conditions of erosion caused by much higher hardness particles,heat treatment is useless to the improvement of erosion resistance of materials although their hardness is increased.But under conditions of erosion by soft particles,the erosion resistance of materials is enhanced by the high hardness obtained by heat treatment.The effect of hardness on erosion is established.When the ratio of particles hardness to material hardness HP/Hm is less than 3,the erosion rate of materials is sensitive to hardness.When Hp/Hm exceeds 3,the influence of hardness on erosion is little.