材料期刊网

在商用09CuPCrNi耐候钢化学成分的基础上,通过调整合金元素含量,研制出了可直接热轧双相化的Cu-P-Cr-Ni-Mo耐候钢。该钢种变形奥氏体的CCT曲线具有较宽的铁素体析出区,可作为热轧＂可行的速度窗口＂;铁素体析出区与贝氏体转变区之间存在约80℃的奥氏体亚稳区,可作为热轧＂可行的卷取范围＂;贝氏体转变区的右侧端部封口,可避免在卷取过程中发生贝氏体转变。根据Cu-P-Cr-Ni-Mo耐候钢的变形奥氏体的CCT曲线,制定了5种热轧双相化工艺,并采用Gleeble-3500热模拟机进行了轧制模拟,制备出了Cu-P-Cr-Ni-Mo热轧双相耐候钢。不同工艺下获得的双相耐候钢组织均为铁素体基体及其上呈岛状分布的马氏体,马氏体体积分数为17%～28%。

Cu-P-Cr-Ni-Mo weathering steel,in which dual-phase microstructures can be obtained by directly hot-rolling,was developed through readjustment of alloy elements based on the composition of weathering steel 09CuPCrNi.The wide temperature range of ferrite precipitation in the continuous cooling transformation（CCT） diagram of the hot deformed austenite can be applied as cooling speed windows.And between the precipitation range of ferrite and the transformation range of bainite,a wide metastable-austenite range of 80 ℃ exists,which can be held as coiling windows.The bainite transformation also can be avoided during the coiling process for the enveloped bainite transformation range in the CCT diagram.Based on the CCT diagram of deformed austenite,dual-phase weathering steel Cu-P-Cr-Ni-Mo is produced through simulated continuous hot-rolling on Gleeble-3500 thermal simulator.The microstructure of the hot-rolled dual-phase weathering steel Cu-P-Cr-Ni-Mo under different conditions is characterized as irregular distribution of island-shaped martensite in the matrix of equiaxed ferrite grains.