采用控轧控冷技术(TMCP)生产合金减量型高强度船板

选择系列工业生产连铸板坯,进行了系统的工场热轧试验,设计出合金减量型屈服强度为355 MPa船板钢的化学成分和控制轧制控制冷却工艺规范。使用5 m宽厚板轧机和在线加速冷却设备,批量生产出合金减量型DH36级宽厚船板。合金减量型船板钢为微合金C-Mn钢,其目标成分(质量分数,%):≤0.18C、≤1.1Mn、≤0.25Si、≤0.02Nb、≤0.015Ti。TMCP要点为:采用二阶段控制轧制,精轧温度900℃,快速冷却(AcC)终冷温度(TFC)在640～710℃之间。通过降低Nb和P含量改善了合金减量钢板焊接热影响区(HAZ)的力学性能。

Hot-rolled economical ship plates produced by TMCP technology

A lean steel-composition combined with controlled rolling and cooling process has been proposed for economically producing hot-rolled high strength ship plates.A series of industrially produced slabs were selected and test-scale controlled rolling and accelerated cooling trials were conducted.Industrial mass production has been realized employing a 5 m width rolling mill coupled with an accelerated cooling system.The chemical composition in mass percent of the economical ship plate steel is proposed: w[C]≤0.18,w ≤1.1,w ≤0.25,w ≤0.02,w ≤0.015.Fine-grained microstructure is achieved via finish rolling at 900 ℃ and accelerated cooling(AcC) with finish cooling temperatures(TFC) at 640-710 ℃.The improvement of mechanical properties of the heat-affected zone of the weld is due to the reduction of Nb and P contents.