高铬铸铁三体腐蚀磨损机理及影响因素的研究

STUDY OF THREE-BODY CORROSION-ABRASION MECHANISM OF HIGH CHROMIUM CAST IRON

本文研究了24%Cr 高铬铸铁在弱酸性介质条件下的三体腐蚀磨损机理及含碳量、稀土残留量等因素对高铬铸铁腐蚀及腐蚀磨损特性的影响,建立了高铬铸铁三体腐蚀磨损机理的解析模型.结果表明:在三体腐蚀磨损过程中,高铬铸铁腐蚀与磨损交互作用特点为铸态条件下以磨损促进腐蚀为主,淬火条件下以腐蚀促进磨损为主;随着含碳量的增加,三体腐蚀磨损抗力呈下降趋势;当铸铁中残留一定数量的稀土元素时,铸态高铬铸铁腐蚀与磨损交互作用的特点转变为以腐蚀促进磨损为主;当有合适的稀土残留量时,高铬铸铁的腐蚀特性与三体腐蚀磨损特性最佳.

The mechanism of three-body corrosion-abrasion of 24%Cr high chromium cast iron in weak acidic medium was investigated.The influence of carbon content and residual rare earth elements on the corrosion-abrasion behavior of high chromium cast iron was also studied.A model of the three-body corrosion-abrasion mecha- nism was established.Experimental results showed that under the condition of three-body corrosiou-abrasiou there existed certain interaction between corrosion and abrasion in 24%Cr high chromium cast iron.In the as-cast state predom- inated the promotion of corrosion by abrasion;but in the querched state predom- inated the promotion of abrasion by corrosion.with increasing carbon content of the iron the three-body corrosion-abrasion resistance decreased.The existence of certain amount of residual rare earth elements in the iron could change the interaction of corrosion and abrasion.The Prefered promotion of corrosion by abrasion transformed into preferred promotion of abrasion by corrosion with the addition of rare earth elements.An optimum corrosion resistance and three-body corrosion-abrasion resistance appeared at 0.095%RE(residual).