密集冷却工艺对大梁钢组织和性能的影响研究

Study on the effect of intensive cooling process on the microstructure and properties of crossbeam steel

利用Fotric-288型热成像仪、Leica DMIRM型光学显微镜、Z600电子拉伸试验机和TIME5310型里氏硬度计研究分析了密集冷却线改造前后M610L大梁钢温度分布、组织和性能的变化。研究结果表明2250热连轧产线冷却线由常规层流冷却改造为密集冷却后,热轧卷在卷取前操作侧和传动侧的边部温降降低了30%~40%,热轧卷两侧边部温降基本对称;热卷的晶粒得到了明显细化,细化程度在8%~16%;密集冷却改造后,热卷宽度方向的硬度和拉伸性能波动得到了降低,性能均匀性得到了明显地提高。

The temperature distribution,microstructure and properties of M610L crossbeam steel during the modification of the intensive cooling line were studied and analyzed by using the Fotric-288 thermal imager,Leica DMIRM optical microscope,Z600 electronic tensile testing machine and TIME5310 Leeb hardness tester.The results show that after the cooling line of 2250 hot continuous rolling line is transformed from conventional laminar cooling to intensive cooling,the edge temperature drop of hot rolled coil at the operation side and transmission side before coiling is reduced by 30%~40%,and the edge temperature drop at both sides of hot rolled coil is basically symmetrical;The grains of the hot coil are obviously refined,with the degree of refinement ranging from 8%to 16%;Moreover,after intensive cooling,the fluctuation of hardness and tensile properties in the width direction of the hot coil has been reduced,and the uniformity of properties has been significantly improved.