摘要
利用光学显微镜、扫描电镜和透射电镜等方法,研究了回火工艺对含V超高强度管线钢组织与力学性能的影响。结果表明,随着回火温度的升高和回火时间的延长,试验钢的强度先上升再降低,伸长率和屈强比增加,冲击性能降低。这主要是由于回火后位错密度降低、M/A岛(martensite-austenite)分解、NbC/Nb(CN)与VC/V(CN)等析出相的形成及聚合长大等因素造成。在600℃×60 min的回火条件下,试验钢综合力学性能优良,其屈服强度、抗拉强度和-20℃冲击吸收能量分别是671 MPa、755 MPa和177 J,均达到超高强度管线钢X100的要求。
Effect of tempering on microstructure and mechanical properties of a vanadium-bearing ultra-high strength steel for pipeline was investigated by means of SEM and TEM analysis. The result indicates that with the increase of either tempering temperature or holding time, the strength of the tested steel increases first and then decreases, elongation and yield ratio increase, and impact toughness decreases. The reason may be due to the decrease of dislocation density, decomposition of M/A （martensite-austenite） constituents, and precipitation and coalescence of NbC/Nb（CN） and VC/V（CN） particles during tempering. When tempered at 600 ℃ for 60 min, the steel specimen can obtain a good combination of mechanical properties, i.e. yield strength of 671 MPa, tensile strength of 755 MPa and impact absorbed energy at - 20 ℃ of 177 J, which meets the requirement of ultra-high strength pipeline steel X100.
出处
《金属热处理》
CAS
CSCD
北大核心
2014年第2期34-38,共5页
Heat Treatment of Metals
关键词
管线钢
回火工艺
组织
力学性能
析出强化
位错
pipeline steel
tempering process
microstructure
mechanical properties
precipitation strengthening
dislocation
