钢包加入、残留痕量稀土对U71Mn钢重轨组织和性能的影响

Effect of Trace Rare Earth on Structure and Properties of U71Mn Steels

采用金相、图像分析和测量HRC等方法,对较洁净的U71Mn钢及其在钢包加入0.02%和0.04%RE、残留稀土为0.0022%～0.0025%的U71MnRE钢重轨的组织与性能进行了"profile"实验研究,同时测量了试验钢热轧态及变形态样品的内耗。结果表明:在VD精炼的钢包加入稀土不仅能有效净化钢质,而且残留的痕量稀土能改变钢的夹杂物、细化珠光体、有效减轻和抑制钢组织与性能的不均匀性。U71MnRE钢里高出的0.06%C增加了钢轨的硬度及嵌镶内应力、应变量,因而增大了SKK阻尼和高温过程组尼。

The profile study on the structure, inclusions and properties of the U71Mn steels in which added without RE and with 0.02% or 0.04%RE (but remained only 0.0022%～0.0025%RE) was carried out by metallographic observation, image analysis and measuring Rockwell hardness etc. The internal frictions of the deformed and un-deformed square wire specimens were also measured. The experiments show that the addition of rare earth in the ladle treated with VD can make steel clean. The remaining only 22～25×10^(-6) RE can make the inclusions to be modified, thin the pearlite out. Besides it can effectively restrict and/or reduce the heterogeneities in the structure and properties. The 0.06% and more carbon in the U71Mn(RE) steels increase the hardness and the amount of inlaid internal stress and strain in the steel rails.