船用耐海水腐蚀埋弧自动焊材料的研制

研制了一种耐海水腐蚀的埋弧焊丝,该焊丝配用３５０焊剂进行施焊,焊接接头具有优良的综合力学性能,满足了船体钢的焊接要求,填补了该强度级别耐海水腐蚀船用焊丝的国内空白。本文对该焊丝的成分设计、焊剂筛选及耐海水腐蚀性能试验等有关情况进行了介绍。     

高强度低合金钢的药芯电弧焊

手工电弧焊、埋弧焊,气保护钨极电弧焊和气保护金属极电弧焊工艺已广泛用于焊接高强度钢。近十年药芯焊丝研究的进展促使开发出某些用于焊接标准高强度钢以及较新型的高强度低合金(HLSA)钢的新型药芯焊丝。本文介绍了有关这些新型药芯焊丝的机械性能、焊缝金属扩散红量和所要求的焊接工艺等方面的技术资料。并将利用特定的焊接应用实例从经济角度讨论药芯电弧焊方法的优点。     

日本潜艇用钢及焊接材料的焊接性能综述

本文综述了日本的潜艇用钢及其焊接材料的各项焊接性能试验情况。对NS63和NS80钢的大量试验结果表明:为了防止产生焊接裂纹,应根据钢种强度级别、板厚和拘束应力的不同来选择不同的预热和道间温度,通常在50~150℃之间变化;相应的焊接热输入也宜在16~24 kJ/cm之内选配,以便得到与焊材相适应的临界冷却速度,使之满足焊缝力学性能的要求。还要限制施焊环境的水蒸气分压(≤25mmHg),焊材的吸潮量要≤0.20%。另外,对NS110钢的低强匹配焊接接头也进行了大量的试验工作,结果表明:在焊缝强度比母材降低15%的条件下仍具有良好的综合性能,将其应用到潜艇壳体上是可以信赖的。     

铝锂合金自动钨极氩弧焊接工艺研究

采用自行研制的两种焊丝,进行了新型铝锂合金自动钨极氩弧焊接,测量了焊态下两种焊丝焊接接头的室温力学性能,观察了接头的显微组织和拉伸断口形貌.并采用鱼骨形抗裂实验,评定了该合金的热裂纹敏感性.实验结果表明,焊接工艺规范显著影响接头的焊缝成形,采用交流脉冲焊接方法和研制焊丝作填充材料可明显改善合金的抗裂性能,焊态下两种研制焊丝的接头强度系数均能达到60%.     

20Cr钢与B级钢焊接接头的组织和性能

采用低温冲击试验、拉伸试验、硬度试验以及金相分析等方法对ER50-6焊丝气体保护焊焊接20Cr钢与B级钢焊接接头的显微组织和性能进行了研究.结果表明,用ERS0-6焊丝气体保护焊焊接20Cr钢和B级钢可获得性能良好的焊接接头,其接头的强度不低于B级钢.焊缝组织为网状分布的先共析铁素体及少量无碳贝氏体;20Cr钢侧近缝区有无碳贝氏体及少量板条马氏体;在B级钢侧热影响区的块状铁素体基体上有少量粒状贝氏体.     

微合金化桥梁用钢14MnNbq匹配H10Mn2焊丝焊接性研究

选用H10Mn2焊丝匹配14Mn Nbq钢,进行了埋弧焊接试验研究,试验结果表明,接头强度及塑性指标满足14Mn Nbq钢焊接要求,接头各区冲击功有很大富余量,焊缝表面下2 mm处硬度值处于理想范围,未出现明显的硬化现象,接头三区金相组织主要以铁素体和珠光体为主,而这类组织具有优良的综合力学性能,满足桥梁用钢焊接技术要求。     

核电承压设备用钢SA738Gr．B焊接性能试验研究

本文通过对SA738Gr．B钢焊接冷裂纹敏感性试验、手工焊和埋弧焊焊接试验,分析了钢板焊接冷裂纹敏感性和焊接接头的综合力学性能及显微组织,结果表明武钢SA738Gr．B钢具有优异的焊接性能,能够满足我国极寒地区核电站用钢要求。     

硬质合金与钢焊接的研究进展

硬质合金与钢的连接可以实现高硬度、高强韧的理想结合,从而极大地拓展硬质合金的应用领域和应用范围。常用的连接方法主要有机械固定和焊接等方法,其中焊接方法因具有连接强度高、稳定性好和服役寿命长等优点被广泛应用。焊接中基于热源类型形成了多种焊接技术,各种焊接技术可获得相应的接头组织和性能以适用于不同要求。本文系统地介绍了当前国内外关于硬质合金与钢焊接的最新研究进展,包括钎焊、扩散焊、电弧焊、高能束焊、复合热源焊、摩擦焊以及电阻焊,对比了这些焊接方法及其焊接工艺对接头力学性能和微观组织的影响。其中,钎焊属于非熔焊接,因具有工艺简单、成本低廉的特点被广泛应用,目前的研究着重于开发各种新型钎料以改善其润湿性,从而提高焊接接头强度;而电弧焊、高能束焊、复合热源焊等熔焊可在焊接界面处产生良好的冶金结合,实现较高强度的连接。然而,熔化焊在界面处不可避免地产生了具有典型特征的η相,由于其脆性而恶化了接头性能。因此,本文综述了各种焊接方法对η相的生成原因及抑制机制,着重介绍了电阻点焊中η相的形核机理和长大模型,最后对未来硬质合金与钢焊接的研究重点和发展方向进行了展望。     

ER5356焊丝中Sc、Zr、Er对7A52铝合金焊接性能的影响

使用传统ER5356焊丝及添加Sc、Zr、Er的ER5356焊丝对7A52铝合金进行钨电极惰性气体保护焊,研究了Sc、Zr、Er对焊接接头力学性能的影响。结果表明,在ER5356焊丝中添加Sc、Zr、Er可有效细化焊缝处的组织,提高焊接接头的强度。单独添加Sc的焊丝效果最好,焊接接头的抗拉强度可达322.5 MPa,是母材强度的70.4%。     

S355钢焊接接头的组织与力学性能

通过拉伸、冲击和金相检验等试验方法对S355钢半自动气体保护焊焊接接头的力学性能与显微组织进行了研究.结果表明:采用JM-56焊丝对S355钢进行焊接时,接头具有较好的抗剪强度和低温冲击韧性;焊缝组织主要为先共析铁素体、针状铁素体、少量珠光体和粒状贝氏体.熔合区、过热区主要为先共析铁素体及较多的珠光体和一定量的粒状贝氏体.     

英国潜艇用钢及其焊接材料

综述了英国潜艇用钢及其焊接材料和工艺最新发展情况,给出了钢板产品的成分性能数据,重点介绍了Q1N钢用焊接工艺的应用情况。在钢板和焊接接头性能验收方面,英国海军采用了与美国海军一些相对不同的考核试验方法,本文对这些试验方法作了简单的介绍。     

Effect of welding wire and groove angle on mechanical properties of high strength steel welded joints

Mechanical properties of high strength steel welded joints strictly depend on the welding process, the filler material composition and the welding geometry. This study investigates the effects of using cored and solid welding wires and implementing various groove angles on the mechanical performance of weld joints which were fabricated employing the gas metal arc welding process. It was found that weld joints of low alloy, high strength steels using low alloy steel cored welding wires exhibited higher tensile strength than that of low alloy steel solid wire and chromium‐nickel steel bare welding wire when the method of gas metal arc welding is employed. The effect of groove angle on the strength and toughness of V‐groove and double V‐groove butt‐joints was investigated. V‐groove joints, with higher tensile strength than double V‐groove joints in the whole range of groove angles, were superior in toughness for small groove angles, but impact toughness values of both joints were comparable for large angles. The effect of heat input and cooling rate on the weld microstructure and weld strength was also investigated by performing thermal analysis employing the commercial software ANSYS. It was concluded that cooling rate and solidification growth rate determined the microstructure of the weld zone which had great consequences in regard to mechanical properties.     

Investigation on various welding consumables on properties of carbon steel material in gas metal arc welding under constant voltage mode

In this present work, the influence of different consumables on weld properties of carbon steel plate was studied by automatic gas metal arc welding under constant voltage mode. For all experiments, the process parameters such as welding current of 200 A, voltage of 28 V and welding speed of 200 mm/min were kept constant. The results indicate that the angular distortion remained higher for solid wire, whereas it was minimum for flux-cored wire and the lowest in metal-cored wire. Mechanical properties such as yield strength, tensile strength, elongation and joint efficiency remained high for solid wire relative to cored wire. Excellent impact toughness of the weld metal and heat-affected zone was reported for the flux-cored welds compared with solid wire and metal-cored welds.     

Development of transition metal joint for steam generator circuit of prototype fast breeder reactor

Abstract

A transition metal joint between type 304 stainless steel and 2·25Cr–1Mo steel, with Alloy 800 as the transition piece, is being developed for application in the steam generator circuit of the 500 MW prototype fast breeder reactor. As part of this programme, the hot cracking susceptibility of Inconel 82/182 and of 16–8–2 welding consumables were compared and the microstructure and mechanical properties of butt welds between type 304 stainless steel and Alloy 800, welded by the two consumables, were studied to select the appropriate welding consumables for this joint. It is recommended that the 16–8–2 consumable should be used for welding this joint because of its lower microfissuring tendency and reduced mismatch in the coefficient of thermal expansion across the joint, although this would mean a slight adverse effect on the elevated temperature mechanical properties. Further, to select the optimum post-weld heat treatment (PWHT) of the joint between Alloy 800 and 2·25Cr–1Mo steel, welded with Inconel 82/182 welding consumables, the effect of PWHT on the microstructure and mechanical properties was studied. Decreasing the PWHT temperature was found to improve the mechanical properties and the microstructural condition of this joint.

MST/842     

10CrSiNiCu钢埋弧焊材料的试验研究

研究了一种可与１０ＣｒＳｉＮｉＣｕ 钢配套使用的埋弧焊焊丝,对焊接后的对接接头进行了力学性能、耐蚀性能等性能测试。结果表明,其焊缝金属力学性能及特种性能均能与母材良好匹配。     

Laser welding of TiNi shape memory alloy and stainless steel using Ni interlayer

Laser welding of TiNi shape memory alloy wire to stainless steel wire using Ni interlayer was investigated. The results indicated that the Ni interlayer thickness had great effects on the chemical composition, microstructure, gas-pore susceptibility and mechanical properties of laser-welded joints. With an increase of Ni interlayer thickness, the weld Ni content increased and the joint properties increased due to decreasing brittle intermetallic compounds (TiFe₂ and TiCr₂). The joint fracture occurred in the fusion zone with a brittle intermetallic compound layer. The tensile strength and elongation of the joints reached the maximum values (372 MPa and 4.4%) when weld Ni content was 47.25 wt.%. Further increasing weld Ni content resulted in decreasing the joint properties because of forming more TiNi₃ phase, gas-pores and shrinkage cavities in the weld metals. It is necessary to select suitable Ni interlayer thickness (weld composition) for improving the mechanical properties of laser-welded joints.     

电弧增材制造AZ31镁合金组织与力学性能分析

针对镁合金在轻量化结构件领域的应用前景,采用基于MIG焊的电弧增材制造工艺开展了两组不同路径的AZ31镁合金增材实验,并对其微观组织和力学性能进行了分析。结果表明：增材构件相较于原始焊丝的化学成分无较大变化;单道次多层往复堆积路径相较于多道次多层堆积路径,更易制得表面更为平整,内部更为致密的构件,其屈服强度为77.3 MPa,抗拉强度为235 MPa,达到原始焊丝75%的力学性能水平,平均显微硬度为52.7HV,断后伸长率最高达到了27%;增材构件拉伸断裂方式为韧性断裂,并在多道次多层往复堆积构件断口处发现其内部存在气孔。验证了电弧增材制造AZ31镁合金工艺的可行性。     

固溶处理对304/Q245R焊接接头组织及性能的影响

为研究固溶处理对304奥氏体不锈钢和Q245R碳钢异种金属焊接接头显微组织及性能的影响,采用E309-16奥氏体不锈钢焊丝对6 mm厚的304/Q245R板材进行手工电弧焊,焊后使用箱式电阻炉对焊接接头进行固溶处理,对焊接接头进行显微组织观察和力学性能测试.结果表明:相对于固溶处理前,固溶处理后的接头焊缝组织为灰色奥氏体和黑色铁素体,枝晶偏析程度明显降低,Cr、Ni等合金元素分布较为均匀;焊缝和碳钢侧热影响区硬度值均有所提高,最高硬度值为304.59 HV,出现在焊缝位置;接头抗拉强度较高,达570 MPa,拉伸断裂发生在母材Q245R碳钢部位.另外,对焊缝进行XRD测定,未检测到不利于接头性能的相,这表明固溶处理后的异种金属接头性能良好,能够满足工程中的实际需求.