摘要
针对中碳调质钢34CrNi1Mo与低合金钢Q355B异种焊接时冷裂纹敏感性高、碳迁移显著及接头性能不均等难题,开展了高效埋弧焊接工艺研究。基于低强匹配原则,选用H10Mn2焊丝与SJ101焊剂组合,并制定了包含预热(200~250℃)、控制层间温度及焊后560℃×8 h退火的关键工艺。试验结果表明,所得接头力学性能优异:抗拉强度(≥490 MPa)满足Q355B母材要求且断裂发生于母材;焊缝、34CrNi1Mo侧热影响区、Q355B侧热影响区的20℃冲击功均值分别为106.3 J、125.2 J、182.2 J;显微硬度呈梯度分布,34CrNi1Mo侧热影响区最高(平均314HBW),Q355B母材最低(平均163 HBW)。金相分析显示焊缝组织为贝氏体+铁素体,热影响区组织过渡均匀。本研究证实所开发的埋弧焊工艺可实现34CrNi1Mo与Q355B异种钢的高质量连接,为工程应用提供了可靠依据。
To address the challenges of high cold cracking susceptibility,significant carbon migration,and mismatched joint properties in welding dissimilar steels between medium-carbon quenched and tempered steel 34CrNi1Mo and low-alloy structural steel Q355B,this study investigates a high-efficiency Submerged Arc Welding(SAW)process.Based on the undermatching principle,a combination of H10Mn2 welding wire and SJ101 flux was selected,supported by key procedures including preheating(200-250℃),strict interpass temperature control,and post-weld annealing at 560℃for 8 hours.Mechanical tests demonstrate excellent joint performance:the tensile strength(≥490 MPa)meets the design requirement,with fractures consistently occurring in the Q355B base metal;the average impact energies at 20℃are 106.3 J for the weld metal,125.2 J for the heat-affected zone(HAZ)on the 34CrNi1Mo side,and 182.2 J for the HAZ on the Q355B side,all exceeding the respective base metal requirements;microhardness exhibits a gradient distribution,with the highest average value in the HAZ on the 34CrNi1Mo side(314 HBW)and the lowest in the Q355B base metal(163 HBW).Metallographic analysis reveals a weld microstructure consisting of bainite and ferrite,with a reasonable microstructural transition in both HAZs and no welding defects.This process successfully achieves high-quality and efficient joining of 34CrNi1Mo and Q355B dissimilar steels,providing reliable parameters for engineering applications.
作者
李园园
李利霞
娄安东
王孟阳
LI Yuanyuan;LI Lixia;LOU Andong;WANG Mengyang(Citic Heavy Industries Co.,Ltd.,Luoyang 471039,China;School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China;State Key Laboratory of Intelligent Mining Heavy Equipment,Luoyang 471039,China)
出处
《电焊机》
2025年第12期72-78,共7页
Electric Welding Machine
关键词
中碳调质钢
异种钢焊接
埋弧焊
低强匹配
力学性能
微观组织
medium carbon quenched and tempered steel
dissimilar steel welding
SAW
undermatching
mechanical properties
microstructure
