低相变温度焊材对Q1100超高强钢焊接接头氢扩散行为和冷裂敏感性的影响  

Effect of Low Transformation Temperature Welding Materials on Hydrogen Diffusion Behavior and Cold Cracking Susceptibility of Q1100 Ultra-High Strength Steel Welding Joints

作　　者：利成宁 邢玉翔 王佳骥 杨兆庆 邸新杰[1,2] Li Chengning;Xing Yuxiang;Wang Jiaji;Yang Zhaoqing;Di Xinjie(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin 300350,China;State Key Laboratory of Metal Material for Marine Equipment and Application,Anshan 114009,China)

机构地区：[1]天津大学材料科学与工程学院,天津300350 [2]天津市现代连接技术重点实验室,天津300350 [3]海洋装备用金属材料及其应用国家重点实验室,鞍山114009

出　　处：《天津大学学报(自然科学与工程技术版)》2025年第4期434-440,共7页Journal of Tianjin University:Science and Technology

基　　金：国家自然科学基金资助项目(52274391).

摘　　要：针对超高强钢焊接接头易产生冷裂纹的问题,选用低相变温度(LTT)焊材和传统ER140S-G超高强钢焊材作为对比,研究了扩散氢调控对Q1100超高强钢焊接冷裂纹敏感性的影响.通过焊接接头临界断裂应力和断口形貌特征分析不同焊接接头的冷裂倾向,并通过焊态氢微印试验,将氢在不同焊接接头中的宏观扩散行为进行可视化表征,进一步分析焊态下不同焊材对于焊接过程中扩散氢抑制作用的差别.Q1100超高强钢碳含量较高,其粗晶热影响区组织为粗化的马氏体板条加少量贝氏体,冷裂倾向明显.插销冷裂纹试验结果表明,LTT焊材能够降低超高强钢焊接接头的冷裂倾向.在焊接参数相同的条件下,LTT-Q1100接头的临界断裂应力达到520 MPa,而ER140S-GQ1100接头的临界断裂应力只有460 MPa.LTT-Q1100接头的断口呈现准解理断裂形貌,ER140S-G-Q1100接头断口韧性恶化明显,多为沿晶断裂形貌,属于脆性断裂,使用LTT焊材提高了超高强钢热影响区的抗冷裂能力.焊态氢微印试验表明:在LTT-Q1100焊接接头中,大量Ag颗粒聚集在焊缝区,热影响区的Ag颗粒很少;而ER140S-GQ1100接头中焊缝区和热影响区均有大量Ag颗粒聚集.使用LTT焊材能够降低焊缝金属的相变温度,在焊接过程中抑制焊接接头中的氢向热影响扩散,从而降低焊接热影响区中的扩散氢含量,降低焊接热影响区的冷裂敏感性.To address the issue of cold cracking in welding joints of ultra-high strength steel,this study compared two welding materials:the low transformation temperature(LTT)welding material and the traditional ER140S-G ultra-high strength steel welding material.We explored how diffusible hydrogen impacts the susceptibility of Q1100 ultra-high strength steel welding to cold cracking.We investigated the cold cracking tendencies in different welding joints by focusing on the critical fracture stress and the appearance characteristics of fractures.We also conducted hydrogen microprint tests to visually represent how hydrogen diffuses in different welding joints,which helped analyze the effectiveness of different welding materials in inhibiting hydrogen diffusion during welding.Q1100 ultra-high strength steel is known for its high carbon content,resulting in a microstructure within its coarse grain heat-affected zone that consists primarily of roughened lath martensite with a small amount of bainite.This combination makes it particularly susceptible to cold cracking.The implant test results showed that LTT welding materials significantly reduce the tendency for cold cracking.Under identical welding parameters,the critical fracture stress of the LTT-Q1100 joint reached 520 MPa,compared to just 460MPa for ER140S-G-Q1100 joint.The fracture surface of the LTT-Q1100 joint showed a quasi-cleavage fracture morphology.By contrast,the ER140S-G-Q1100 joint exhibited mostly intergranular fracture patterns,characteristic of brittle fractures,indicating a more ductile nature.The use of LTT welding materials improved the cold crack resistance of the heat-affected zone of ultra-high strength steel.Hydrogen microprint tests demonstrated a high concentration of Ag particles in the weld zone of the LTT-Q1100 welding joint,with fewer particles present in the heat-affected zone.A large amount of Ag particles were accumulated in the weld zone and heat-affected zone of the ER140S-G-Q1100 joint.The use of LTT welding materials could reduce the pha

关 键 词：超高强钢 焊接冷裂纹 LTT焊材 ER140S-G焊材 氢微印试验 扩散氢 

分 类 号：TG422.3[金属学及工艺—焊接]