75钢热轧盘条的热模拟试验分析  

Experimental Analysis of Thermal Simulation of 75 Steel Hot Rolled Wire Rod

作　　者：黄小山 闫博 李声延 张春斌 邱冬 HUANG Xiaoshan;YAN Bo;LI Shengyan;ZHANG Chunbin;QIU Dong(Xinyu Iron and Steel Group Co.,Ltd.,Xinyu 338001,China)

机构地区：[1]新余钢铁股份有限公司,江西新余338001

出　　处：《山东冶金》2023年第4期31-34,共4页Shandong Metallurgy

摘　　要：利用Gleeble 3800对75钢进行热模拟试验,测得试验钢的相变点温度Ac_(1)为731℃、Ac_(3)为786℃、M_(s)为238℃。当冷却速率>15℃/s时,铁素体转变会终止;当冷却速率>20℃/s时,开始发生马氏体转变的温度为238℃。当冷却速率<10℃/s时,显微组织为珠光体+少量铁素体;当冷却速率>15℃/s时,奥氏体全部生成珠光体;当冷却速率超过20℃/s时,马氏体含量越来越多,同时硬度也不断上升。生产75钢热轧盘条的控冷工艺为吐丝后先以10~12℃/s的冷却速率冷却至560~585℃,然后进行缓慢冷却。批量生产的75钢盘条的抗拉强度1 038~1 126 MPa,断面收缩率为42%~53%,组织为索氏体+珠光体+少量铁素体,没有生成中心马氏体或网状渗碳体,索氏体级别1~1.5级,盘条综合性能较好。Gleeble 3800 was used to perform thermal simulation tests on 75 Steel.The phase transition point temperatures of Ac_(1),Ac_(3) and M_(s)were 731℃、786 Cand 238 C respectively.When the cooling rate is higher than 15 C/s,the ferrite transition will stop.When the cooling rate is greater than 20 C/s,begin to occur martensitic transformation temperature is 238 C.When the cooling rate is less than 10C/s,the microstructureispearlite plus a small amountofferrite.When the cooling rate is higherthan 15C/s,all austenite forms pearlite.When the cooling rate exceeds 20 C/s,the martensite content is increasing,and the hardness is also increasing.The controlled cooling process for 75 steel hot rolled wire rod is to first cool the wire at a cooling rate of 10-12 C/s to 560-585℃,and then slow cooling.The tensile strength of the mass production of 75 Steel wire rod is 1038-1126 MPa,the section shrinkage rate is 42%-53%,the structure is sortenite+pearlite+a small amount of ferrite,no formation of central martensite or network cementation,sortenite is grade 1-1.5,the comprehensive performance of the wire rod is good.

关 键 词：75钢 热模拟试验 CCT曲线 相变 

分 类 号：TG142.15[一般工业技术—材料科学与工程]