大截面DIEVAR钢模块固溶冷却行为的数值研究

Numerical Study on Solid Solution Cooling Behavior of DIEVAR Steel Block with Large Section

以尺寸为470 mm×800 mm×4 000 mm的大截面DEVAR热作模块为研究对象,采用DEFORM建立模块固溶冷却过程的数值模型,研究了模块在水冷和油冷及两种固溶冷却工艺下的冷却行为、组织演变及应力演变规律,并从理论角度预测了模块可生产的最大规格。结果表明,水冷和油冷的模块心部均可避开碳化物析出,油冷下模块心表温差更小;两种冷却介质及工艺下模块心部最终组织的体积分数差异很小;模块表面和心部主要表现为热应力和组织应力;DIEVAR模块水冷和油冷的理论最大厚度分别为550、580 mm。

By taking a DIEVAR steel block messuring470mm by800mm by4000mm as the research object,the numerical model of steel block during solid solution cooling was established by using a deform-D software.The cooling behavior,microstructure and effective evolution of the block under water cooling and oil cooling and two solid solution cooling processes were researched,and the largest specification of DIEVAR steel block that can be manufactured was evaluated form the theoretical perspectives.The results showed that the core of steel block cooled in water and oil can avoid carbide precipitation,temperature difference between core and surface by oil cooling was lower than that of water cooling;The volume fraction of microstructure in the core of steel block cooled by two cooling medium and procedures was almost the same;The stresses at surface and the core of block were thermal stress and structural stress;The maximal theoretical thicknesses of the block were550mm in water and580mm in oil.