镁对21-4N气阀钢中碳化物的影响  

Effect of Mg on carbides in 21-4N valve steel

作　　者：季灯平 朱浩然 刘贝贝 孙晗 徐翔宇 付建勋 Ji Dengping;Zhu Haoran;Liu Beibei;Sun Han;Xu Xiangyu;Fu Jianxun(School of Materials Science and Engineering,Shanghai University,Center for Advanced Solidification Technology,State Key Laboratory of Advanced Special Steel,Shanghai 200444,China;Zhejiang Qingshan Iron and Steel Co.,Ltd.,Lishui 325000,Zhejiang,China)

机构地区：[1]上海大学材料科学与工程学院,先进凝固技术中心,省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]浙江青山钢铁有限公司,浙江丽水325000

出　　处：《钢铁钒钛》2024年第3期195-199,共5页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金资助项目(51874195,52074179)。

摘　　要：为了探究不同镁含量对21-4N气阀钢中液析碳化物的影响规律,采用实验室高温电阻炉冶炼了不同镁添加量的21-4N气阀钢,借助蔡司金相显微镜、扫描电子显微镜、电解腐蚀等方法开展研究。结果表明,随21-4N钢中Mg含量的增加,碳化物平均最大尺寸及面积占比均先减小后增大。添加微量的镁有助于改善钢中富Cr型液析碳化物的尺寸和分布,镁的质量分数为1.6×10^(-5)时,液析碳化物平均最大尺寸为60.55μm,面积占比10.43%,在钢中多呈颗粒状分布,连续性被破坏,其原因是镁元素在晶界处的偏聚,能够抑制C、Cr等合金元素的扩散,阻断碳化物连续生长,从而达到细化碳化物尺寸的效果。In order to explore the influence of different magnesium content on primary carbides in 21-4N valve steel,21-4N valve steel with different magnesium content was smelted in a laboratory high temperature resistance furnace,and the research was carried out by use of Zeiss metallographic microscope,scanning electron microscope and electrolytic corrosion.The results show that with the increase of Mg content in 21-4N steel,both the average maximum size and area ratio of carbides firstly decrease and then increase.The addition of trace magnesium is helpful to improve the size and distribution of Cr-rich precipitated carbides in steel.When the mass fraction of magnesium is 1.6×10^(-5),the average maximum size of precipitated carbides is 60.55μm and its area ratio is 10.43%,and most of them are granular in steel,and the continuity is destroyed.The reason is that the segregation of magnesium at the grain boundary can inhibit the diffusion of alloy elements such as C and Cr,and then block the continuous growth of carbide,thus achieving the effect of refining the carbide size.

关 键 词：21-4N气阀钢 镁改质 液析碳化物 

分 类 号：TF76[冶金工程—钢铁冶金]