铁基合金抗冲蚀性能主要控制因素的分析

ANALYSIS ON PREDOMINANT FACTORS CHARACTERIZING EROSION RESISTANCE OF SOME FERROUS ALLOYS

用旋转圆盘实验机对2种超弹性Fe-Mn-Si-Cr形状记忆合金、5种Cr-Ni不锈钢和1种新型高铬铸铁的抗冲蚀性能进行了研究,通过SEM和XRD以及犁削抗力和局域弹性的模拟测定,探索了硬度、犁削抗力,弹性性质和相变对抗冲蚀性能的影响．结果表明,冲蚀微观失效机制是泥沙犁削．犁削抗力W_p与局域弹性h_e是不锈钢和Fe-Mn-Si-Cr形状记忆合金抗冲蚀性能的主要控制因素。其冲蚀率R_e与局域弹性h_e值和犁削抗力W_p值之间存在着相关性较高的量化表征关系式．相变在抗冲蚀性能中的作用取决于局域弹性h_e和犁削抗力W_p的综合效应．形状记忆合金0Mn25Cr7Si6Cu抗冲蚀性能因诱发的密排六方ε马氏体具有高的局域弹性h_e而优于除高铬铸铁以外的所有其它实验材料．

Erosion resistances of two Fe-Mn-Si-Cr shape memory alloys and five Cr-Ni stainless steels have been compared with a high chromium iron using a rotating disc rig. Based on SEM, XRD and simulative measurements of plough-cutting resistant capacity Wp and localized surface layer elasticity he for the tested alloys, the influences of hardness, Wp, he and phase transformation on the resistance of the alloys were discussed. The results show that the micro-failure mechanism is ploughcutting of sand particles in the erosion process. Wp and he are predominant factors characterizing the resistance of the stainless steels and shape memory alloys, and there exists a good quantitative formula indicating correlation of he and Wp with erosion rate Re. The role of phase transformation in the resistance depends on the synthetic effect of Wp and he of the induced martensite, and the resistance of shape memory alloy 0Mn25Cr7Si6Cu is better than that of the other tested alloys except the high chromium iron because of the lager he of the induced ε martensite.