任启蒙，陈林

1内蒙古科技大学 材料与冶金学院，内蒙古，包头，014010

2包头钢铁（集团）钢管公司，内蒙古，包头,014010

关键词：高强度；高韧性；冷成型；中厚板

中图分类号：TG335.5 文献标志码：A

摘要：本文基于某宽厚板生产线，采用调质工艺开发了一种屈服强度690MPa级高强度工程机械用钢，钢板微观组织为板条状贝氏体，晶粒均匀、板条束尺寸细小。经检验，钢板的屈服强度Rp0.2达到780MPa，抗拉强度Rm达到864MPa，延伸率A达到18%。此外，钢板具有优良的低温冲击韧性，–20℃条件下冲击吸收功可以达到260J以上；–40℃条件下冲击吸收功可以达到250J以上；–60℃的超低温条件下其最低冲击吸收功依然可以达到238J。钢板也具有良好的冷成型性能，可以满足严格的加工和严苛的服役要求。

Research and Developmentof 690MPa Grade High Strength Steel with High Toughness

REN Qi-meng，CHEN Lin

1.Materials and Metallurgy School，Inner Mongolia University of Science and Technology，Baotou 014010，China；2.Pipe Company, Baotou Iron and Steel(Group)Co.,Baotou 014010，China.

Key words:high strength; high toughness; cold-bending; heavyplate

Abstract:Ahigh strength plate with yield strength of690 MPa was developed based on a heavyplate mill by quenching and tempering process. The microstructure of plate isbainite. All grains were small and uniform. The size of bainite lath is thin. Theyield strength Rp0.2, tensile strength Rm, and elongation A of the plate reached780 MPa, 864 MPa, and 18.0%,respectively. The Charpy absorbed energy is higherthan 260 J at -20℃ and also higher than 250 J at -40℃. The lowest Charpy absorbedenergy can reach 238 J even at -60 ℃. Especially, the plate also has goodcold-bending properties.