摘要
在实验室用真空感应炉冶炼3炉X65管线钢,其中2炉钢进行镁处理。分析非镁处理钢和镁处理钢中夹杂物的变化特征,研究镁处理对X65管线钢中夹杂物的影响。结果表明:1)非镁处理钢中的夹杂物主要是Al_2O_3系夹杂,镁处理钢中的夹杂物类型主要是MgO-Al_2O_3系夹杂;2)镁处理钢中粒径小(1~5μm)的夹杂物比例相对较高,大颗粒(> 15μm)夹杂物明显减少;3)粒径较大的夹杂物主要是Al_2O_3夹杂和靠近低熔点区域的夹杂,靠近镁铝尖晶石成分的夹杂物粒径较小,说明镁处理可使钢中夹杂物变得细小而分散;4)镁处理钢中存在大量的尺寸细小的MgO·Al_2O_3系夹杂物,可以为硫化物的析出提供形核核心,从而减少硫化物在晶界的析出数量。
Three heats of X65 pipeline steel were produced in a laboratory, two of which were treated with magnesium. The characteristics of inclusions in steel were analyzed by SEM-EDS and ASPEX. And the influence of magnesium treatment on inclusions was studied. The results show that, 1） the oxide inclusions in steel without magnesium treatment are mainly Al2O3 inclusions, while the oxide inclusions are mainly MgO-A1203 in the steel with magnesium treatment. 2） The proportion of the small size （1 -5μm） inclusions in magnesium-treated steel is relatively high,and that of large size （〉15μm） inclusions is obviously reduced. 3） The composition of large-size inclusions are mainly Al2O3 and that close the low-melting-point zone. The inclusions close to MgO · Al2O3 spinel composition have smaller size, indicating that the magnesium treatment could make the size of inclusions smaller and disperse the inclusions. 4） Magnesium-treated steel contained a large number of fine MgO·Al2O3 inclusions, which could provide nucleation core for the precipitation of sulfide, and thus reduce the precipitation of sulfide at the grain boundary.
作者
田俊
王德永
屈天鹏
王慧华
苏丽娟
TIAN Jun;WANG Deyong;QU Tianpeng;WANG Huihua;SU Lijuan(Shagang School of Iron and Steel in Soochow University,Suzhou 215021,China)
出处
《炼钢》
CAS
北大核心
2018年第5期43-49,共7页
Steelmaking
基金
国家自然科学基金资助项目(51704200
51674172
51774208)
江苏省自然科学基金资助项目(BK20150336
BK20150334)
关键词
管线钢
镁处理
夹杂物
MNS
pipeline steel
magnesium treatment
inclusion
MnS
