超快冷条件下低合金钢板的合金减量化生产工艺实践

摘要

With completion of technical transformation in Tangshan Heavy Plate Company,especially the start-up of ultra-fast cooling device (UFC),the cooling capacity after rolling is significantly improved,which lays a solid foundation for higher grade medium and heavy steel development.If the original chemical composition design for the ACC condition is still used for the UFC condition,it foresees too much alloy redundancy and wide margin for further cost reduction,which is of important and practical value for alloy decrement of low alloy steel plate production under UFC condition.Tangshan Heavy Plate Co., Ltd.designs six kinds of composition in three systems including C-Mn,C-Mn-Nb-Ti and C-Mn-Nb-Ti-V in order to investigate the effect of re-tempering temperature on actual mechanical properties of steel plate.The test results show that reducing re-tempering temperature can significantly improve the mechanical properties of steel plate,esp.for thicker steel plate.Based on the production process practice of alloy drecrement,the Company realizes stable production of 80 mm thick 460 MPa grade steel plate with good flatness.%随着唐山中厚板材有限公司生产线技术改造的完成,特别是超快冷(UFC)设备投入使用,轧后冷却能力得到明显提升,为高级中厚板品种开发奠定了基础.但如果在超快冷(UFC)条件下仍然使用原来在加速冷却(ACC)条件下使用的成分设计,将导致合金富余量过大,成本具有进一步下降的空间,因此在超快冷条件下低合金钢板的合金减量化生产具有重要的实用价值.唐钢为此设计了C-Mn、C-Mn-Nb-Ti和C-Mn-Nb-Ti-V 3个体系6种成分,并在试验中分析研究返红温度对钢板实物性能的影响.试验结果表明:降低返红温度能够显著提高钢板的力学性能;钢板厚度增加时,适当降低返红温度,其力学性能也同样能够得到保证.通过合金减量化生产工艺实践,唐山中厚板材有限公司实现了80 mm厚度460 MPa强度级别钢板的稳定生产,且板型良好.