ZHOU Min
,
DU Lin-xiu
,
LIU Xiang-hua
钢铁研究学报(英文版)
The variation of heat treatments including directed quenching and tempering off-line after controlled rolling (DQT) and quenching off-line and tempering off-line after controlled rolling (RQT) with microstructure and mechanical properties of a low-carbon microalloyed steel was compared and analyzed. For DQT, the quenched steel was obviously banded microstructure, with increasing tempering temperature, lath martensite coarsened, the cusp carbide precipitated at grain boundaries, the yield strength fluctuated slightly, and the fracture-separation was obvious. The impact toughness was better in the steel tempered at 500 ℃ for 1 h. In RQT, with increasing tempering temperature, lath martensite degenerated, intragranular and intergranular finer precipitations with smaller than 30 nm precipitated and grew up and were distributed dispersedly, the stripe-like carbides were distributed at grain boundaries, and the yield strength and tensile strengthen decreased obviously. The impact toughness of RQT process was much better than that of DQT process, and the comprehensive mechanical properties were better for the steel tempered at 500 ℃ for 1 h of RQT process.
关键词:
X120 pipeline steel
,
heat treatment
,
microstructure
,
mechanical property
,
fracture-separation
郑跃强
,
唐兴昌
,
李积鹏
,
王云平
钢铁研究
doi:10.13228/j.boyuan.issn1001-0963.20140368
在实验室试制了X120管线钢,并绘制了X120管线钢的连续冷却转变曲线.结果表明:热轧态时试验钢的屈服强度平均值为905MPa,抗拉强度平均值为980 MPa,伸长率平均值为17％,屈强比为0.92,-20℃的冲击功平均值为90J.经600℃回火2h后,试验钢的屈服强度平均值达到了950MPa,抗拉强度平均值达到了1000 MPa,伸长率平均值为18％,屈强比为0.95,-20℃的冲击功平均值为95J.经过压缩后,冷却速度为5℃/s时试验钢的组织即全部为板条贝氏体组织,而该组织为X120级管线钢中的理想组织.
关键词:
X120管线钢
,
组织
,
力学性能
,
CCT
