利用实验室盐浴热处理炉,对Ø15 mm GCr15风冷盘条进行盐浴等温热处理模拟试验,分析等温盐浴温度对盘条组织和网状碳化物的影响.结果表明:盐浴温度在525℃及以下进行等温冷却,盘条组织中存在马氏体,球化退火后网状碳化物不大于2.0级,抗拉强度1 770～1 920 MPa,断面收缩率1％～8％;盐浴温度在550 ℃以上进行等温冷却,盘条组织中无马氏体,且晶界渗碳体未成网状封闭,球化退火后网状碳化物不大于2.5级,抗拉强度1 550～1 710 MPa,断面收缩率25％～33％.盐浴等温冷却盘条的晶界渗碳体尺寸和网状碳化物级别均优于风冷盘条.
Effect of isothermal cooling temperature on microstructure and carbide network of GCr15 wire rod
Using laboratory salt bath heat treatment furnace,salt bath isothermal heat treatment simulation experiment was conducted on diameter 15 mm GCr15 air cooled wire rod to analyze effect of isothermal salt bath temperature on microstruc-ture and carbide network of GCrl5 wire rod.Results show that isothermal cooling is carried out at salt bath temperature 525 ℃ or below,martensite exists in wire rod structure.After spheroidization annealing,carbide network not more than 2.0 grade,with tensile strength 1 770～1 920 MPa and cross sectional shrinkage rate is 1％～8％;Isothermal cooling is car-ried out at salt bath temperature 550 ℃ or above.There is no martensite in wire rod structure,and grain boundary carbides are not enclosed in network.After spheroidization annealing,carbide network not more than 2.5 grade,with tensile strength 1 550～1 710 MPa and cross sectional shrinkage rate is 25％～33％.Grain boundary carbide size and carbide network level of salt bath isothermal cooling wire rod are better than those of air-cooled wire rod.
万方数据
维普
