摘要
近年来,以液化天然气(Liquefied Natural Gas,LNG)双燃料动力为主的绿色船舶数量急剧增加,LNG储罐用高锰钢作为其关键低温材料之一引起越来越多的关注。为通过合金化设计提高LNG储罐用高锰钢的强韧性,系统研究了合金元素种类和增量等对强度和低温冲击韧性的影响规律,分析了低温轧制和轧后冷却方式对组织性能的影响。结果表明,置换固溶元素Ni、Mo和Al可提高屈服强度,而Cr对屈服强度影响不大,Mn降低屈服强度;除Mo之外,其他合金元素均降低抗拉强度;但置换固溶元素均可改善低温冲击韧性。间隙固溶元素C可同时提高屈服强度和抗拉强度,但会损害低温冲击韧性。微合金元素Nb和V主要通过抑制再结晶来提高强度,且部分再结晶组织恶化低温韧性,另外,添加质量分数为0.3%的Nb或0.5%的V才可产生显著的强化效果。高锰钢的强化往往伴随低温冲击韧性的恶化,使得高强韧高锰钢开发存在困难,但本研究发现基于Al添加的固溶强化、细晶强化以及变形机制调控可在有效提高强度的同时获得优异的低温冲击韧性。确定了获得优异低温冲击韧性的室温层错能范围为40~44 mJ/m^(2),估算了Ni、Mo、Cr、Mn、Al和C的固溶强化系数分别为7.0、32.0、0.5、-3.0、22.0和290.0 MPa/%。本研究为高强韧高锰钢的设计提供试验支撑。
Recently,there is a sharp increase in the number of Liquefied Natural Gas(LNG)dual-fuel green ships.It is attracted more and more attentions that high Mn steels for LNG tank building act as one of key cryogenic materials.Effects of alloying elements and their increments on strength and cryogenic impact toughness were systematically investigated in order to enhance strength and cryogenic impact toughness of high Mn steels for LNG tank building by alloying design.Effects of low-temperature hot-rolling and cooling modes on microstructure and mechanical properties were also analyzed.The results show that the substitutional solid solution elements of Ni,Mo and Al have positive effect on yield strength,Cr has negligible effect on yield strength,and Mn has negative effect on yield strength.Except for Mo,the tensile strength is lowered by the other substitutional solid solution elements.However,the cryogenic impact toughness can be improved by the substitutional solid solution elements.The yield strength and tensile strength can be simultaneously enhanced by interstitial solid solution element of C,whereas it deteriorates cryogenic impact toughness.The strength can be also enhanced by microalloying elements of Nb and V,which can retard recrystallization.Moreover,the partially recrystallized structures are harmful to cryogenic impact toughness.In addition,the obviously strengthening effect can be realized for the addition of 0.3%Nb or 0.5%V(mass fraction).But they deteriorate cryogenic impact toughness.The strengthening of high Mn steels is always accompanied by the deterioration of cryogenic impact toughness,leading to a difficulty in developing high Mn steels with high strength and toughness.However,it is found that the strength can be effectively enhanced and excellent cryogenic toughness can be also obtained at the same time by solid solution strengthening,grain boundary strengthening and deformation mechanism controlling on the basis of Al addition.The excellent cryogenic impact toughness can be obtained for the stac
作者
陈俊
刘宁
刘振宇
王国栋
CHEN Jun;LIU Ning;LIU Zhenyu;WANG Guodong(The State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 11o819,Liaoning,China;Technology Center,Hunan Valin Lianyuan Iron and Steel Co.,Ltd.,Loudi 4170o9,Hunan,China)
出处
《中国冶金》
CAS
CSCD
北大核心
2023年第6期73-80,共8页
China Metallurgy
基金
中央高校基本科研业务费资助项目(N2107009)
辽宁省自然科学基金优秀青年基金资助项目(2021-YQ-05)。
关键词
金属材料
高锰钢
合金化
屈服强度
低温冲击韧性
metallic material
high Mn steel
alloying
yield strength
cryogenic impact toughness
