摘要
对新型建筑用25CrMoNiVNbTi超高强度钢在室温下的组织和性能进行了评价。采用拉伸实验、硬度测试、示波冲击测试、金相显微镜、扫描电镜和透射电镜等手段评价了25CrMoNiVNbTi超高强度钢的强度、硬度、韧性和微观组织及其精细结构。结果表明:新型建筑用25CrMoNiVNbTi超高强度钢具有很好的强韧性,室温下该钢的抗拉强度达到1100 MPa左右,冲击功达到100J左右。冲击断口分析表明断面有较多的韧窝,为韧性断裂,微观组织分析表明该钢调质处理后的组织为回火索氏体,晶界处含有较多位错,位错相互缠结产生较强的应力场,从而显著提高了钢的强度。镍的添加和粒状回火索氏体结构使得该钢具有较好的韧性。
Microstructure and properties of a new and super-strength 25 CrMoNiVNbTi steel used in building at room temperature were evaluated in the paper.Strength,hardness,toughness,microstructure and fine structure were investigated or tested by tensile test,hardness test,oscillographic impact testing,metallographic microscope,scanning electron microscopy（SEM）and transmission electron microscopy（TEM）,respectively.The results showed that25 CrMoNiVNbTi steel performed good strength and toughness,the tensile strength of it reached 1100 MPa and impact energy reached 100 J.Dimples on the impact fracture indicated that the fracture was a ductile one,microstructure of the steel after thermal refining was observed as a tempered sorbite.Many dislocations existed in grain boundaries,and the strength of the steel was distinctly improved by stress field that produced by the dislocations tangled to each other.Thanks to the granular tempered sorbite and addition of nickel,25 CrMoNiVNbTi steel performed nice toughness.
基金
住房和城乡建设部科学技术项目资助(2014-K4-036)
油气藏地质及开发工程重点实验室开放基金课题(PLN1416)
