轧后冷却方式对高强度焊丝用盘条显微组织和拉拔性能的影响  

Effect of cooling process after hot-rolling on microstructure and drawing property of wire rod for high strength welding wire

作　　者：甄先锋 李阳 王广顺 侯建伟 郑同亮 Zhen Xianfeng;Li Yang;Wang Guangshun;Hou Jianwei;Zheng Tongliang(Qingdao Branch,CITIC Pacific Special Steel Research Institute,Qingdao Shandong 266409,China;Wire Rod Research Institute,Qingdao Special Steel Co.,Ltd.,Qingdao Shandong 266409,China;Wire Rod Business Department,Qingdao Special Steel Co.,Ltd.,Qingdao Shandong 266409,China)

机构地区：[1]中信泰富特钢研究院青岛分院,山东青岛266409 [2]青岛特殊钢铁有限公司线材研究所,山东青岛266409 [3]青岛特殊钢铁有限公司线材事业部,山东青岛266409

出　　处：《金属热处理》2023年第7期176-181,共6页Heat Treatment of Metals

摘　　要：利用热膨胀仪和盐浴炉分别研究了C-Si-Mn-Mo-Ti焊丝的连续冷却和盐浴等温相变特点,并在高速轧机线材生产线上分别采用斯太尔摩延迟冷却工艺和在线盐浴工艺完成了盘条的工业试制,然后进行了免退火拉拔试验。结果表明,C-Si-Mn-Mo-Ti焊丝钢在0.1~20℃/s的速度范围内连续冷却时无法避免马氏体和贝氏体的产生,且马氏体和贝氏体均呈块状,尺寸与铁素体晶粒尺寸相近。盐浴处理后贝氏体和马氏体含量升高,贝氏体呈未完全长大的颗粒状形态,马氏体尺寸也大幅减小至几微米,且呈均匀弥散分布。轧后采用斯太尔摩延迟冷却工艺生产的盘条在拉拔加工过程中心部出现大量块状马氏体导致频繁断丝,断口呈杯锥状,而采用在线盐浴工艺生产的盘条则可以免退火直接拉拔至成品焊丝,未出现断丝。Characteristics of continuous cooling and isothermal phase transformation of C-Si-Mn-Mo-Ti welding wire were studied by means of thermal dilatometer and salt bath furnace,respectively.The industrial trial production of wire rod was completed by using Stelmor delayed cooling process and on-line salt bath process on the wire rod production line of high speed rolling mill,and then the non-annealing drawing test was carried out.The results show that the formation of martensite and bainite cannot be avoided when the C-Si-Mn-Mo-Ti welding wire steel is continuously cooled in the rate range of 0.1-20 ℃/s,and the formed martensite and bainite are in block shape of the equivalent size to the ferrite grain.After salt bath treatment,the content of bainite and martensite increases,the bainite shows an incompletely grown granular morphology,the martensite size greatly reduces to only a few microns,and their distribution is uniform and dispersed.When the wire rods produced by Stelmor delayed cooling process,brittle fracture with cup-shaped fracture caused by a large number of massive martensite of block shape occurs frequently in the core of the wire rods during the non-annealing drawing test,while the wire rods produced by in-line salt bath process are not fractured during the non-annealing drawing test,which can be directly drawn to the finished wire without annealing.

关 键 词：焊丝钢 在线盐浴 斯太尔摩延时冷却 拉拔 

分 类 号：TG142.1[一般工业技术—材料科学与工程]