摘要
通过膨胀法结合金相-硬度法测定了一种低镍高强耐候钢的奥氏体连续冷却转变(CCT)曲线,研究了冷却速度对其显微组织和硬度的影响。结果表明:该钢屈服强度为510 MPa,屈强比为0.74,-40℃下的冲击吸收能量为72.8 J,耐蚀性显著优于Q345B;临界点温度Ac1为730℃,Ac3为871℃,Ms为383℃;当冷却速度由0.1℃/s增加到100℃/s,实验钢显微硬度值由142 HV0.5增大至320 HV0.5,并依次发生铁素体转变、珠光体转变、贝氏体转变和马氏体转变,其中当冷却速度超过20℃/s时,珠光体消失,组织主要由贝氏体和马氏体组成。
Continuous cooling transformation(CCT) curves of a low nickel high strength weathering steel were determined by means of expansion method combined with metallographic-hardness method, and the effect of cooling rate on microstructure and hardness of the steel was studied. The results show that the yield strength of the tested steel is 510 MPa, the yield ratio is 0.74, the impact absorbed energy at-40 ℃ is 72.8 J, and the corrosion resistance is significantly better than that of the Q345 B steel. The critical temperature Ac1 of the tested steel is 730 ℃, the Ac3 is 871 ℃, and the Ms is 383 ℃. When the cooling rate increases from 0.1 ℃/s to 100 ℃/s, the micro-hardness of the tested steel increases from 142 HV0.5 to 320 HV0.5, and the ferrite transformation, pearlite transformation, bainite transformation and martensite transformation take place in turn. When the cooling rate exceeds 20 ℃/s, the pearlite disappears, and the microstructure of the tested steel is mainly composed of bainite and martensite.
作者
姚纪坛
孙力
年保国
潘进
罗扬
任帅
赵楠
YAO Ji-tan;SUN Li;NIAN Bao-guo;PAN Jin;LUO Yang;REN Shuai;ZHAO Nan(HBIS GROUP Technology Research Institute,Shijiazhuang 050023,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2020年第11期129-134,共6页
Transactions of Materials and Heat Treatment
关键词
低镍高强耐候钢
CCT曲线
显微组织
low nickel high strength weathering steel
CCT curve
microstructure
