ER50-6热轧盘条质量控制与轧制工艺研究

为了使ER50-6焊接用盘条不经退火拉拔至Φ0.8 mm成品,且在拉拔中模具损耗正常,对ER50-6焊接盘条的质量进行分析,要求盘条表面无明显缺陷如折叠、耳子、结疤等,金相组织应为铁素体和少量珠光体,铁素体体积分数应在80%以上,抗拉强度在560 MPa以下。针对影响拉拔质量的有关因素,对轧制工艺进行控制,开轧温度在955~970℃,终轧(减定径)温度在860~900℃,吐丝温度在800~820℃,轧后冷却速度为0.55~0.85℃/s;轧制过程中严控各道次料型尺寸,使轧槽、导卫等处于良好的工作状态,保证轧后盘条组织状态和表面质量及尺寸精度,使用时,细丝拉拔速度可达15 m/s,成品焊接后熔敷金属抗拉强度可达530 MPa。

Quality control and rolling technology research of ER50-6 hot rolled wire rod

The quality of ER50-6 wire rod for welding is analyzed for the purpose that ER50-6 wire rod for welding can be drawn to diameter 0.8mm finished product without annealing,and die wearing is normal in drawing.The fact that there are no obvious defects such as overlap,wulst and scar in wire rod surface is required.Microstructure is ferrite and little pearlite,volume fraction of ferrite is over 80%,tensile strength is below 560 MPa.Aiming at the factors affecting drawing quality,the rolling process is adjusted,start rolling temperature is from 955℃ to 970℃,finish rolling（size reducing）temperature is from 860℃ to 900℃,wire laying temperature is from 800℃ to 820℃,cooling speed after rolling is 0.55℃/s to 0.85℃/s,size of each pass billet shape should be controlled strictly in rolling process,groove and guide are in good working condition,the structure condition,surface quality and size precision of wire rod after rolling can be guaranteed.Fine wire drawing speed can reaches 15m/s in production,the tensile strength of deposited metal after finished products welding reaches over 530MPa.