焊管2024，Vol.47Issue(11)：34-38,5.DOI:10.19291/j.cnki.1001-3938.2024.11.005
热输入对超高强钢焊接接头组织与性能的影响
Influence of Heat Input on Microstructure and Properties of Ultra-high Strength Steel Welded Joints
摘要
Abstract
1 500 MPa grade ultra-high strength steel was subjected to gas metal arc welding(GMAW)with different heat inputs.The hardening zone of the welded joints was analyzed through hardness distribution tests and digital image correlation(DIC)tensile tests.The impact toughness of the coarse-grained heat-affected zone(CGHAZ)was compared,and the effect of heat input on joint embrittlement behavior was examined using metallographic observations.Results show that the microstructure types for both heat inputs are consistent,with the weld region mainly composed of bainite,acicular ferrite,and quasi-polygonal ferrite,while the CGHAZ is predominantly composed of lath martensite,forming an embrittled zone with a hardness reaching 550HV10.When the welding heat input was increased from 29 kJ/cm to 47 kJ/cm,significant coarsening occurred in the weld and CGHAZ microstructures,severely degrading the impact toughness of the CGHAZ from 47 J to 19 J.The softening zone of the welded joints was located on the weld side of the fusion line,and both high and low heat input joints fractured at the weld location.The tensile strength of the joints was 704 MPa and 628 MPa for low and high heat inputs,respectively,with strain concentration occurring at the junction between the root weld and the second layer in high heat input welding,and at the inner side of the fusion line in the middle weld layer in low heat input welding.关键词
超高强钢/热输入/焊接接头/微观组织/力学性能Key words
ultra-high strength steel/heat input/welded joints/microstructure/mechanical properties分类
矿业与冶金引用本文复制引用
闫强军,巴凌志,梁川,邢萍,利成宁,刘丽华,邸新杰..热输入对超高强钢焊接接头组织与性能的影响[J].焊管,2024,47(11):34-38,5.基金项目
国家自然科学基金项目"低碳含铜超高强钢可控相变焊接接头氢扩散及抗氢脆机理研究"(项目编号52274391). （项目编号52274391）
