转向架用P355NL1钢MAG多层焊微观组织及温度场分析  

Microstructure and Temperature Field Analysis of MAG Multi-layer Welding of P355NL1 Steel for Metro Bogies

作　　者：尤君 罗涛 刘睿祖 王建峰 YOU Jun;LUO Tao;LIU Ruizu;WANG Jianfeng(CSR Nanjing Puzhen Vehicle Co.,Ltd.,Nanjing 210031,China;College of Materials Science and Technology,Nanjing University of Aeronautics&Astronautics,Nanjing 211106,China)

机构地区：[1]中车南京浦镇车辆有限公司,南京210031 [2]南京航空航天大学材料科学与技术学院,南京211106

出　　处：《南京航空航天大学学报(自然科学版)》2025年第1期66-72,共7页Journal of Nanjing University of Aeronautics & Astronautics

摘　　要：为进一步提升地铁转向架P355NL1钢材的熔化极活性气体保护(Metal active gas,MAG)多层焊焊接质量,开展了P355NL1钢地铁转向架对接接头MAG多层焊接试验,分析了对接结构的宏观及微观形貌,重点研究了每一层的焊缝及热影响区的组织,建立了对接接头MAG多层焊接模型并进行校核,探明了MAG多层焊温度场的分布规律。结果表明,在MAG多层焊接试验中,后道焊缝的热输入通过两次相变重结晶作用,破坏了前道焊缝中的柱状晶结构,此过程使得前道焊缝晶粒细化,形成了细小的铁素体晶粒和少量珠光体。双椭球热源模型可以有效模拟P355NL1钢MAG多层焊焊接过程,后道焊缝焊接时最高温度显著升高,因此在多层焊的焊接过程中,控制填充层的焊接温度对于细化晶粒组织至关重要。To further enhance the metal active gas(MAG)multi-layer welding quality of P355NL1 steel used in metro bogies,this paper conducts the MAG multi-layer welding tests of the butt joint of P355NL1 steel metro bogies,analyses the macro and micro morphologies of the butt joint structure,focuses on the study of the weld and the organisation of the heat-affected zone of each layer,establishes a MAG multi-layer welding model of the butt joint and performs calibration,and studies the distribution law of the temperature field of the MAG multi-layer welding.The results indicate that in the MAG multi-layer welding experiment,the heat input from the subsequent weld passes two phase transformations and recrystallization,which disrupts the columnar grain structure in the previous weld pass.This process leads to the refinement of the grain structure,forming fine ferrite grains and a small amount of pearlite.The double ellipsoid heat source model effectively simulates the welding process of P355NL1 steel in MAG multi-layer welding.The maximum temperature significantly increases during the welding of the upper layers.Therefore,controlling the welding temperature of the filler layers is crucial for grain refinement in multi⁃layer welding processes.

关 键 词：MAG多层焊 地铁转向架 微观组织 温度场 

分 类 号：TG442[金属学及工艺—焊接]