冷却工艺对低焊接裂纹敏感性钢组织的影响  

Effect of Cooling Technology on Microstructure of Low Welding Crack Susceptibility Steel

作　　者：兰亮云[1] 邱春林[1] 赵德文[1] 高秀华[1] 杜林秀[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《中国冶金》2011年第2期29-33,共5页China Metallurgy

基　　金：国家自然科学基金资助项目(50474015)

摘　　要：采用弛豫控制析出+加速冷却(RPC+ACC)和超快速冷却+加速冷却(UFC+ACC)2种不同冷却工艺试制低裂纹敏感性钢板,结合显微硬度、SEM及TEM技术分析了冷却工艺对显微组织及力学性能的影响。结果表明:RPC+ACC工艺试样的屈服强度和抗拉强度比UFC+ACC工艺高170 MPa和65 MPa,而且维持了相同的冲击韧性。获得含有大量位错胞的板条贝氏体组织,且不同尺寸的板条贝氏体被亚结构或位错墙分割,出现相互交错排列是RPC+ACC冷却工艺提高强度的主要机制。Two different cooling processes,namely,relaxation-precipitation-control phase transformation＋acceleration cooling（RPC＋ACC） and ultra fast cooling＋acceleration cooling（UFC＋ACC） were used to produce low welding crack susceptibility steel.The effects of these cooling processes on microstructure and mechanical properties were analyzed by means of microhardness,SEM and TEM.The results showed that the yield strength and tensile strength of the RPC＋ACC samples were 170MPa and 65MPa more than that of the UFC＋ACC samples respectively,and kept the same toughness.The main strengthening mechanism of the RPC＋ACC process was that lath bainite ferrite was refined by recovery of dislocation and the form of substructure,and fine lath bainite ferrites staggering arrangement and including high density dislocation were obtained by acceleration cooling.

关 键 词：低焊接裂纹敏感性钢 冷却工艺 板条贝氏体 MA组元 

分 类 号：TG335[金属学及工艺—金属压力加工]