低裂纹敏感性特厚钢板610CF的热处理工艺

Heat treatment process of 610CF steel plate with low crack sensitivity

通过对610CF相变点、冷却曲线的测定,结合生产淬火临界厚度的模拟分析,研究了610CF钢板的亚温淬火＋回火的热处理工艺,并优化了亚温淬火温度、回火温度,确定830℃淬火组织。结果表明,830℃淬火获得铁素体与马氏体、贝氏体组织,经640～660℃回火后可获得最佳的强度和韧性匹配,为最优热处理工艺,保证了低裂纹敏感性特厚钢板610CF的各项性能均满足大型水电工程高强度低焊接裂纹敏感性钢板的技术要求。

The sub-critical quenching and tempering heat treatment process of 610 CF steel plate was studied by measuring the phase transition point and cooling curve of the steel and the simulation analysis of the critical thickness of quenching.The sub-critical quenching temperature and tempering temperature were optimized,and the microstructure of the steel plate at 830 ℃ was specified.The results show that the ferrite,martensite and bainite structure are obtained by quenching at 830 ℃,and the best combination of strength and toughness can be obtained after tempering at 640-660 ℃,which can be the optimal heat treatment process,and ensures that the performance of the low crack sensitive ultra-thick steel plate 610 CF meets the technical requirements of high strength and low welding crack sensitive of the steel plate for large hydropower project.