ER69-3盘条退火过程晶界氧化问题分析与改进  

Analysis and improvement of grain boundary oxidation during annealing process of ER69-3 wire rod

作　　者：侯建伟 左锦中 亓奉友 董强 苏永泽 Hou Jianwei;Zuo Jinzhong;Qi Fengyou;Dong Qiang;Su Yongze(CITIC Taifu Special Steel Research Institute Qinggang Branch,Qingdao 266400,China)

机构地区：[1]中信泰富特钢研究院青钢分院,山东青岛266400

出　　处：《金属制品》2024年第5期33-39,共7页Metal Products

摘　　要：ER69-3作为工程机械用70 kg级焊丝钢的代表牌号,其热轧盘条在720℃保温3.5 h退火后,经过机械除鳞和拉拔、镀铜等工序加工的焊丝表面出现“发黑”现象,“发黑”的焊丝表面存在较多裂纹缺陷,对应的退火盘条存在明显晶界氧化现象。通过单变量试验,确认退火盘条的晶界氧化主要是因为退火温度设定较高,在720℃时氧化铁皮中的氧从晶界向基体扩散,产生晶界氧化。试验通过降低退火温度至670℃或酸洗去除氧化铁皮后再进行720℃退火处理两种措施,均可保证退火后消除马氏体和贝氏体组织,同时确保退火盘条几乎不产生晶界氧化,解决了退火盘条加工过程中焊丝表面“发黑”的问题。ER69-3 is representative brand of 70 kg grade welding wire steel for construction machinery.After hot rolled wire rod is annealed at 720℃for 3.5 h,welding wire surface processed by mechanical descaling,drawing,copper plating and other processes appears blackening.There are many crack defects on blackened welding wire surface,and corresponding annealed wire rod has obvious grain boundary oxidation.Through single variable test one by one,it is confirmed that grain boundary oxidation of annealed wire rod is mainly due to high setting of annealing temperature.At 720℃,oxygen in oxide scale diffuses from grain boundary to matrix,resulting in grain boundary oxidation.By reducing annealing temperature to 670℃or removing oxide scale by pickling and then annealing at 720℃,martensite and bainite structures can be eliminated after annealing,and grain boundary oxidation of annealed wire rod is almost avoided,which solves problem of blackening on welding wire surface during annealing process of wire rod.

关 键 词：ER69-3 焊丝 酸洗 退火 晶界氧化 机械除鳞 

分 类 号：TG142.1[一般工业技术—材料科学与工程]