热处理条件对X60钢高频焊管焊缝组织和性能的影响

摘要

On-line heat treatment process of X60 steel weld seam welded by high-frequency welding (HFW) technology was simulated by means of a muffle furnace in the lab,and the effects of normalizing temperature on microstructure and properties were studied.The results show that the microstructure of HFW seam was composed of acicular ferrite,polygonal ferrite,bainite and pearlite.With the increase of normalizing temperature,the amount of bainite gradually decreased,until vanished away,and the grain sizes of welded seam,heat affected zone and base material increased gradually.The tensile strength of HFW seam gradually decreased,and the impact absorbing energy first increased and then decreased with the increase of normalizing temperature.After normalizing at 920 ℃,the tensile strength of HFW seam was 532 MPa and the impact absorbing energy was up to maximum of 139 J.Comparing with the grain size of the welded seam after on-line heat treatment at 920 ℃,the grain size after simulation heat treatment at the same normalizing temperature in the lab was a little bigger,but the tensile strength and toughness of them were almost the same.%在试验室利用马弗炉模拟了X60钢高频焊接(HFW)焊缝的在线热处理,研究了正火温度对其组织与性能的影响.结果表明:未热处理的HFW焊缝组织为针状铁素体、多边形状铁素体、贝氏体和珠光体；随正火温度升高,贝氏体数量逐渐减少直至消失,焊缝、热影响区和母材的晶粒尺寸逐渐增大；随正火温度的升高,HFW焊缝的抗拉强度逐渐降低,冲击吸收功则先升后降,在920℃正火后,焊缝的抗拉强度为532 MPa,冲击吸收功最大,为139 J；920℃在线热处理后焊缝的晶粒尺寸与实验室模拟的相同正火温度下的晶粒尺寸相比略显粗大,但它们的抗拉强度和冲击韧性基本相当.