-35℃低温下珠光体/贝氏体钢轨磨损与滚动接触疲劳行为研究

Study on rolling wear and rolling contact fatigue behavior of pearlite/bainite rail steels at the low temperature of −35 ℃

高寒地区铁路钢轨面临着低温服役环境,低温下钢轨的滚动磨损与损伤行为是影响其服役安全的重要因素。通过轮轨滚动接触模拟试验研究了-35℃温度下珠光体(亚共析钢和共析钢)和贝氏体钢轨磨损与滚动接触疲劳(RCF)损伤行为。结果表明,贝氏体钢轨在-35℃试验温度下硬化程度较低,导致磨损程度高于珠光体钢轨,珠光体钢轨中亚共析钢轨磨损程度低于共析钢轨;三种钢轨存在不同程度的RCF损伤,疲劳裂纹主要以小角度(<10°)扩展。磨损和RCF存在竞争关系,磨损较小的亚共析钢轨RCF损伤严重,共析钢轨次之,磨损最严重的贝氏体钢轨RCF损伤最轻微。

The rail in the high altitude and high latitude regions faces the low temperature service environment.The rolling wear and damage behaviors under low temperature are the significant factors influencing the rail service safety.The wear and rolling contact fatigue(RCF)damage laws of pearlite rail steels(hypoeutectoid and eutectoid)and bainite rail steel were explored at the low temperature of−35℃using wheel/rail rolling contact simulation experiments.The results showed that the hardening degree of bainite rail was lower at−35℃,and the wear degree was higher than those of pearlite rails.The wear degree of hypoeutectoid rail steel was lower than that of eutectoid rail steel.Different RCF damage levels occurred on the explored three kinds of rail steels.Cracks mainly propagated with small angles(<10°).There was a competitive relationship between the wear and RCF.The RCF damage of hypoeutectoid rail steel with less wear was serious,followed by eutectoid rail,and the RCF damage of bainite rail steel with the most severe wear was the mildest.