【作者】 吕艳丽；

【导师】 石忠贤； 华学明；

【作者基本信息】 上海交通大学 ， 材料加工工程， 2012， 硕士

【摘要】 船舶工业是为国防建设、航运交通和海洋开发提供主要装备的战略性产业,焊接技术是船舶生产的关键技术之一。而高速、高效的多丝焊(双丝焊和三丝焊)是当前国内外焊接领域所关注的研究课题。本文开展了多丝GMAW对船用E级钢焊接接头性能和质量的影响研究。研究成果将为船舶制造企业采用高效、高速、优质的多电极弧焊技术,提高其制造技术水平提供技术支持。本文构建了三丝对接焊焊接试验平台。开展了单丝焊、双丝焊及三丝焊焊接工艺参数对焊缝成形的影响研究,同时进行了工艺参数对船用E级钢焊接接头微观组织演变规律的研究;基于焊接接头拉伸强度和-40℃的夏氏V型缺口冲击试验及硬度测定,研究了微观组织与接头性能之间的影射关系。试验结果表明:(1)以堆焊作为切入点,发现单丝焊/双丝焊/三丝焊的焊接效率近似满足1:2:3;三丝焊的两相区为细小P及块状F组织;细晶区以B粒为主并包含少量块状F组织;粗晶区以B粒为主并含有极少量B上;焊缝为柱状F先、B粒和少量F针。另外,当线能量分别为42500J/cm,34000J/cm,28333J/cm时,三丝焊堆焊组织和硬度并没有明显变化。(2)在文中焊接参数下,对接焊焊缝成形良好,且单丝焊/双丝焊/三丝焊的对接焊速度近似满足2:5:8。(3)三丝对接焊微观组织分别为焊缝区F先+P+粒状B+针状F;粗晶区和细晶区同为P+F,但细晶区晶粒细小;两相区为细小P+块状F。组织对比可见,单丝焊/双丝焊/三丝焊的微观组织分布基本相同,但单丝焊和双丝焊的焊缝区出现B上。(4)参考NB/T 47014-2011焊接工艺评定标准,三丝焊对接接头抗拉强度为560MPa,断裂发生在母材;焊缝-40℃的冲击功为44J;冲击断口形貌以准解理断裂为主,并包含少量解理断裂和韧窝断裂。更多还原

【Abstract】 Shipbuilding industry is a strategic industry, which provides major equipments to national defense, marine exploitation. And welding technology is one of the key technologies about shipbuilding. High-speed, high-efficient multi-wire welding is current domestic and international research focus. This paper launched the influence of multi-wire GMAW to marine grade E steel welded joint performance and quality. And this research can provide technical support of high-efficient, high-quality multi-wire welding to ship-build enterprises.This paper built the three-wire butt welding test platform. Studied the single-/twin-/triple-wire welding process, and the microstructure . Besides, basing on tensile strength of welded joints, hardness measurement and -40℃V-notch impact test , the paper studied the relationship between microstructure and mechanical properties of welding joints .The results showed that: (1) About build-up welding, the single-/twin-/triple-wire welding efficiency ratio approximately meet 1:2:3. The microstructure of triple-wire welding is similar to single/ twin-wire welding. In addition, when the linear energy of triple-wire welding are 42500J/cm,34000J/cm,28333J/cm, the hardness and microstructure did not change significantly. (2) Get the fine butt welding parameters. The single-/twin-/triple-wire welding efficiency ratio approximately meet 2:5:8. (3) The microstructure of triple-wire welding is: pro-eutectoid ferrite +P+ granular bainite + acicular ferrite in weld seam; P+F in fine grain zone and coarse grain zone; block F and small P in two-phase region.(4) The tensile strength of triple-wire welding was 560MPa, and the fracture occurred at the base metal; the impact toughness was 44J at -40℃; Impact fracture morphology mainly quasi-cleavage fracture, and contained a small amount cleavage and dimple fracture. These mechanical meet the welding procedure qualification standards (NB/T 47014-2011).更多还原