2205双相不锈钢薄壁小径管钨极氩弧焊接头组织和性能  

Microstructure and mechanical properties of GTAW joint of 2205 duplex stainless steel small-bore thin wall tube

作　　者：师金凤 雷玉成[1] Shi Jinfeng;Lei Yucheng(Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学,江苏镇江212013

出　　处：《焊接》2021年第9期34-38,63,共6页Welding & Joining

摘　　要：采用钨极氩弧焊方法,以ER2209为填充材料,98%Ar+2%N_2作为保护气体,对φ18 mm×1.5 mm小管径、薄壁2205双相不锈钢管进行了焊接,利用无损检测、力学性能试验及金相组织观察等手段研究了2205双相不锈钢超薄壁小径管焊接接头的组织和性能。结果表明,焊缝成形良好,焊接接头抗拉强度为668 MPa,不低于母材,断裂位置发生在热影响区,母材、热影响区及焊缝硬度260~280 HV,满足ASTM A790标准要求,并且焊接接头具有良好的抗弯曲性能;相间边界平滑,无不良金属间化合物相;根据ASTM E562标准方法检测热影响区中铁素体含量,约占50%~70%,和奥氏体组织两相比例基本平衡;焊接接头抗点蚀性能满足ASTM G48标准要求,其腐蚀率最大5.1 mg/(dm·d)。2205 duplex stainless steel small-bore thin wall tube with φ18 mm × 1. 5 mm was welded by tungsten inert gas welding with ER2209 filler material and 98% Ar + 2% N2 shielding gas. Microstructure and mechanical properties of 2205 duplex stainless steel ultra-thin wall small diameter pipe welded joint were studied by means of nondestructive testing, mechanical properties test and metallographic observation. The results indicated that weld was well formed, and tensile strength of welded joint was 668 MPa, no less than that of the base metal.The fracture occurred in the heat-affected zone. The hardness of the base metal, heat affected zone and weld was 260 ~ 280 HV, which met ASTM A790 standard. The welded joint had good bending resistance. The phase boundary was smooth and there were no harmful intermetallic phases. According to ASTM E562 standard method, ferritic content in heat affected zone of welded joint was about 50% ~ 70%, which was basically balanced with austenite. The pitting corrosion resistance of welded joint met the requirement of ASTM G48 standard, and the measured maximum corrosion rate was 5. 1 mg/(dm·d).

关 键 词：2205双相不锈钢 薄壁小径管 焊接接头 力学性能 组织 

分 类 号：TG442[金属学及工艺—焊接]