稀土元素镧对Q355B低合金高强度钢组织和性能的影响  

Effect of Rare Earth Element La on Microstructure and Properties of Q355B Low Alloy High Strength Steel

作　　者：魏慧慧 黄利[2] 袁晓鸣[2] 高雪云[1] 王海燕[1] WEI Huihui;HUANG Li;YUAN Xiaoming;GAO Xueyun;WANG Haiyan(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Technical Center of Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,包头014010 [2]内蒙古包钢钢联股份有限公司技术中心,包头014010

出　　处：《机械工程材料》2025年第3期68-73,共6页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(52161008,51961030);中央引导地方科技发展资金资助项目(2020ZY0034);内蒙古自治区直属高校基本科研业务费资助项目(2023QNJS025)。

摘　　要：采用真空熔炼方法制备了含质量分数0.0021%稀土元素镧的Q355B低合金高强度钢,研究了试验钢的显微组织、冲击和拉伸性能以及在NaHSO3溶液中的耐腐蚀性能,并与未添加镧的试验钢进行对比。结果表明:未添加和添加镧的Q355B钢组织均为铁素体+珠光体,镧的加入降低了组织的元素偏析程度,减少了带状组织,并提高了晶粒尺寸的均匀性;未添加镧的试验钢中存在尺寸约为267μm的棱角分明的串状Al_(2)O_(3) 夹杂物,而添加镧后夹杂物为球状稀土复合硫氧化物,尺寸显著减小,约为10μm。镧的添加对试验钢拉伸性能的影响不大,但可以提高其冲击性能,与未添加镧的试验钢相比,添加镧后的冲击吸收能量提高了5.2%。与未添加镧的试验钢相比,添加镧后试验钢的腐蚀质量损失率降低了5.5%,腐蚀产物层更致密,耐腐蚀性能更好。Q355B low alloy high strength steel containing rare earth element La with mass fraction of 0.0021%was prepared by vacuum melting method.The microstructure,impact and tensile properties and the corrosion resistance in NaHSO3 solution of the test steel were studied,and were compared with those of the test steel without rare earth element La.The results show that the microstructure of Q355B steel without and with La was ferrite and pearlite,and the addition of La decreased the element segregation degree of the structure,reduced the band structure,and improved the uniformity of grain size.The test steel without La had angular string Al_(2)O_(3) inclusions with the size of about 267μm;after adding La the inclusions were spherical rare earth complex sulfur oxides,and the size significantly decreased to about 10μm.The addition of La had no significant influence on the tensile properties of the test steel,but could improve the impact properties.Compared with that of the test steel without La,the impact absorption energy after adding La increased by 5.2%.Compared with those of the test steel without La,the corrosion mass loss rate of the test steel with La was reduced by 5.5%,the corrosion product layer was denser and the corrosion resistance was better.

关 键 词：稀土元素镧 低合金高强度钢 显微组织 耐腐蚀性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]