铸造Ti-Al-Mo-Zr钛合金电子束焊接接头组织与性能

选用电子束焊接方式对14 mm厚铸态Ti-Al-Mo-Zr钛合金进行焊接,在合适的工艺参数下获得成形良好、无内部缺陷的焊接接头。室温下测试与分析焊接接头的显微组织、显微硬度和力学性能,结果显示焊缝处主要由β相基体和粗大的针状α相组成,热影响区处受焊接热循环作用部分转变为网状片层组织。焊缝处硬度略高于母材处,接头整体硬度分布均匀,无明显弱化区域;接头焊缝处抗拉强度优于母材,焊缝处冲击值AKV达到75 J/cm~2,热影响区冲击值为73 J/cm~2,Ti-Al-Mo-Zr钛合金电子束焊接接头冲击韧性良好。     

Modeling of temperature field and pool formation during linear laser welding of DP1000 steel

A rotary-Gauss body heat source was employed in the study to model the laser welding of DP1000 steel. The condition of heat dissipation during the welding has a significant effect on the temperature field as well as the shape and size of the laser weld. A series of welding experiments were performed, and good agreement was observed between the calculated weld dimensions and the experimental results. The microhardness values across the welded joint were measured to determine the range of the soft zone in the heat affected zone (HAZ) and simultaneously the temperature range experienced in this region. The results indicated that the soft zone significantly affects the mechanical performance of the welded joint. The width of the soft zone and its distance from the weld center increase with increasing laser power, while the width of the soft zone and its distance from the weld center decrease with increasing welding speed.     

铝合金双光束/单光束激光-TIG复合焊

针对4mm厚5A06铝合金,分析了双光束光纤激光-TIG复合焊的焊缝成形特点、气孔率、匙孔动态特征及接头力学性能,并与单光束光纤激光-TIG复合焊对比。结果表明,在获得相同焊缝背面熔宽条件下,与单光束激光-TIG复合焊相比,双光束激光-TIG复合焊的焊缝背面成型连续性、均匀性更优且熔宽波动较小,焊缝气孔率降低50%以上,激光匙孔开口面积平均值更大,波动变异系数更小;双光束激光-TIG复合焊接头抗拉强度、断后伸长率、显微硬度、组织与单光束激光-TIG复合焊结果差别不大。     

镀锌薄板TIG拼焊的焊缝组织及成形性能

采用钨极惰性气体焊对镀锌薄板 SGCC 实施等厚拼焊,测试分析了拼焊板焊接接头的金相组织、显微硬度,并对拼焊板和母材试样进行杯突试验.结果表明,在拼焊过程中,母材的散热情况不同会造成焊缝金相组织在靠近母材的局部区域有很大差异.焊缝熔合区组织为粗的片状与块状先共析铁素体沿柱状晶界分布,晶内为魏氏体组织和片状珠光体,热影响区为块状的珠光体和铁素体,导致了焊缝及其热影响区的硬度均高于母材,对拼焊板的整体成形性能产生负面影响;同时,焊缝杯突值较母材有一定程度的降低,揭示其焊缝深冲性能低于母材.

Abstract：

The microstructure and micro-hardness of welded joint of SGCC by tungsten inert-gas (TIG) welding are studied, and the cupping test of Tailor-welded blank and base metal are studied.The results show that in the welding process, the microstructure of weld will have great diversity at local region closing parent metal because of the different cooling condition of the parent metal. The microstructure of welding fusion zone is massive sheet proeutectoid ferrite distribution along the columnar grain boundaries, intragranular organizations are Widmanstatten and sheet pearlite structure, and the microstructure in HAZ is massive pearlite and ferrite, which make the micro-hardness value of welding seam and HAZ higher than that of base metal and lead negative influence to the formability of Tailorwelded blank. The cupping value of weld seam reduces to some extent compared with that of base metal, which indicates that the formability of weld seam is not good as that of base metal.     

PM-TZM钼合金电子束焊接特性

为研究PM-TZM钼合金电子束焊接特性,对其进行了电子束焊接试验,分别对接头显微组织及力学性能进行了分析. 结果表明,PM-TZM钼合金电子束焊缝呈“钉状”几何特征,熔合线附近有链状气孔出现. 焊缝区由粗大的等轴晶及柱状晶组成,热影响区晶粒相比于母材明显长大. 接头各区域硬度值不同,焊缝区硬度与母材相当,硬度最低值出现在两侧热影响区.PM-TZM合金电子束焊接接头有较大的性能损失. 接头室温最高抗拉强度378 MPa,为母材抗拉强度的47%,1 000℃抗拉强度168 MPa. 接头拉伸断裂均发生于焊缝区,呈典型的脆性解理断裂特征.     

FSS/ASS厚壁异种钢“TIG冷焊 + UNGW”组合焊的接头组织与力学性能

为了有效解决铁素体不锈钢的焊接热影响区晶粒易粗化问题，以及奥氏体不锈钢焊接时在接头部分熔合区及其附近热影响区内因易形成蠕虫状δ铁素体而显著降低该区域耐腐蚀性的问题，提出了“TIG冷焊 + UNGW”的组合焊接工艺，并进行了1Cr17/1Cr18Ni9Ti厚壁异种不锈钢的焊接，同时对所得接头的显微组织、力学性能及耐腐蚀性进行了测试与分析. 结果表明，组合焊接头的1Cr17母材热影响区晶粒未发生粗化，并且1Cr18Ni9Ti母材部分熔合区及其附近热影响区内未形成蠕虫状δ铁素体；组合焊接头的抗拉强度优于1Cr17母材，并且1Cr17母材热影响区的冲击吸收能量与1Cr17母材相当；组合焊接头的熔敷层、1Cr18Ni9Ti母材、1Cr17母材、UNGW焊缝区及完整接头的耐腐蚀性呈依次下降的趋势.     

超声冲击处理冷轧钢板缝焊接头的疲劳性能

用窄搭接电阻缝焊机对汽车用SPCC（冷轧低碳普通钢板）进行焊接,采用超声冲击仪对缝焊接头进行处理;通过拉压疲劳试验、X射线应力分析仪、OM、SEM对处理和未处理的缝焊接头疲劳性能和组织进行测试和观察分析对比.结果表明,未经超声冲击处理的缝焊接头经5×104次交变载荷作用即在焊趾区萌生裂纹,裂纹与载荷方向呈45°;经超声冲击处理过的缝焊接头经1.88×106次交变载荷作用未发生断裂;超声冲击处理使缝焊接头表层晶粒细化并形成塑性变形层,降低了其表面的微裂纹缺陷造成的应力集中,使表面残余拉应力变为了压应力,有利于改善缝焊接头的疲劳性能.     

A304不锈钢薄板激光焊工艺试验研究

研究利用激光焊接技术焊接A304不锈钢薄板的工艺.试验过程中,采用一系列激光焊参数焊接试板,然后将焊接接头制成金相试样,观察熔深、熔宽、热影响区的大小,比较连续激光和调制方波脉冲激光焊接不锈钢薄板的效果.     

等离子弧焊Q345B和430不锈钢异种接头的微观组织与性能

摘要： 采用等离子弧焊对3 mm厚的Q345低合金钢与430不锈钢进行异种钢焊接,并对接头微观组织、力学性能及耐腐蚀性能进行了研究。结果表明,当转弧电流为100 A时,等离子弧焊Q345B/430异种钢接头的焊缝组织为均匀分布的马氏体及针状铁素体,焊接接头综合性能优良。随着电流的增大,焊缝组织转变为粗大板条马氏体及铁素体。两侧热影响区组织均发生一定程度的粗化,且Q345B侧热影响区出现魏氏组织。焊接接头于焊缝处显微硬度最大,不同转弧电流条件下异种钢显微硬度分布趋势大致相同。不同转弧电流下,焊接接头抗拉强度均与430不锈钢相近,且均断裂在靠近焊缝的430母材侧,转弧电流为100 A时接头抗拉强度最大值427 MPa。焊接接头的耐腐蚀性能与焊接电流呈负相关趋势。 创新点： 试验结果为铁素体低合金钢与铁素体不锈钢异种钢接头的应用提供了工艺数据与支撑。     

Characteristics of 5A90 Aluminum-lithium Alloy by YAG-MIG Hybrid Welding

The characteristics of 5A90 Aluminum-Lithium alloy by YAG laser and MIG arc hybrid welding (Hybrid welding) were studied.Compared with the laser beam welding (LBW),the hybrid welding could not only improve the weld appearance significantly,but also have better engineering compatibility.The obvious microstructure characteristics of joint by the hybrid welding are fine-grained layer near fusion-line and the equiaxed grain in most area of welded seam.The subgrains of the equiaxed grains,located in the weld center,tend to coarse from bottom to top of weld joint.The microhardness of welded seam by the hybrid welding (83.57HV0.2) is lower than that by LBW (95.65HV0.2),but the uniformity of the former is better than that of the latter.The ultimate strength and the elongations after fracture of the joint by the hybrid welding are lower than that by LBW.The tensile fracture always occurs in HAZ or weld centerline,and the fractography presents mixture rupture.Therefore,if the combined mechanical properties of joint by the hybrid welding meet the operation requirements,it should be improved by reasonable artificial aging or heat treatment after welding,and it also should develop a better filler wire matched with the base metal.     

铝合金电流强化激光焊接焊缝组织及性能

采用电流强化激光焊接方法对3.0 mm厚的2219-T6铝合金板材进行堆焊,研究了电流对激光焊缝宏观和微观组织、气孔缺陷以及力学性能的影响.试验发现,引入电流后,焊缝区的晶粒发生明显细化,促使粗大的柱状晶转变为细小的等轴晶;而且消除了激光焊缝中央存在的羽毛状晶.与激光焊接相比,电流强化激光焊接焊缝中的气孔明显减少,接头...     

激光焊接速度对核级不锈钢腐蚀性能的影响

文中对在不同激光焊接速度下得到的核级不锈钢焊接接头进行了核电模拟溶液常温腐蚀试验、点腐蚀和晶间腐蚀试验和高温高压水应力腐蚀试验. 结果表明,随着焊接速度增大,焊接接头维钝电流上升,点蚀电位上升. 在同一焊接接头中,热影响区的耐点蚀性能和晶间腐蚀性能最好,焊接接头整体其次,焊缝区最差. 最低焊速下得到的焊接接头容易产生高温高压水SCC,其SCC裂纹一般从焊道根部的热影响区萌生和扩展.     

DH590钢板激光束焊的焊接特性研究

对厚1.5mm规格DH590钢板进行激光束焊焊接试验,研究该钢板的激光束焊焊接特性以及焊接接头性能。结果表明,1.5 mm规格的DH590+Z钢板单板的最大焊接速度为6.8 m/min,搭接板最大焊接速度为3.2m/min;连续搭接试验的平均最大抗剪力为41.6 k N,断续搭接试验的平均最大抗剪力为18.9 k N,焊接接头的平均最大抗拉力为12.5 k N;焊接接头焊缝区的显微硬度分布均匀,热影响区不存在明显的软化点;对焊接接头进行X光探伤检测,未发现气孔和裂纹缺陷,焊缝质量良好。     

两种TIG焊工艺对LD10接头力学性能的影响

对5.5 mm厚度的LD10(2A14-T6)铝合金进行了两种工艺的TIG焊接,采用热电偶测定了接头的热循环曲线,分析了不同工艺对接头力学性能的影响.结果表明,两面三层焊热影响区中同一点先后经历三次热循环,导致过时效区硬度大幅下降,拉伸时断裂于此;焊缝区各层所经历的热过程不同,导致其硬度起伏较大.与两面三层焊相比,单面两层焊有更高的抗拉强度,为358.3 MPa,热影响区范围窄,且过时效区硬度比三层焊时高,但焊缝中气孔和晶界网状分布的第二相的存在使焊缝和接头的塑性相对降低.     

Study on the strength and failure modes of laser welded galvanized DP980 steel lap joints

The mechanical properties of different sections of the laser welded galvanized high strength dual phase (DP) 980 steel lap joint such as the hardened zone (fusion zone and the grain coarsened heat affected zone (HAZ)), the softened zone (subcritical HAZ), and the base material were determined through mini-tensile tests. The numerically-predicted load–displacement curve and the sample rotation angle were verified by experimental measurements. The FE model considering the non-homogeneous mechanical properties was built based on the weld cross section geometries that were obtained under various laser welding conditions. The numerically-predicted von Mises equivalent strain concentrations and failure modes of the galvanized DP980 lap joints with respect to different laser welding conditions exhibit reasonable agreement with the experimental results.     

中厚板钛合金激光-CMT复合焊接工艺特性分析

通过采用激光-CMT焊接的方法对10 mm厚TC4钛合金实现了不开坡口单面焊双面成形,并对焊缝的组织、力学性能及腐蚀性能进行了测试分析. 结果表明,该最优参数下形成的焊接接头中主要由大量的α'马氏体及初生的α相构成,且存在网篮状组织,焊缝区域的显微硬度大于母材区域,可达380 HV,且由于激光作用区拥有更大的冷却速度,焊缝底部生成了更多的α'马氏体,导致焊缝底部硬度比电弧作用区更高. 焊接接头抗拉强度可达到916 MPa,断后伸长率达到16.08%,拉伸断裂结果为韧性断裂,焊缝组织的性能明显优于母材.焊缝处的抗腐蚀性能优于母材,这是因为焊缝组织有更细小的晶粒及大量位错,提升了钝化能力并阻碍了Cl?的扩散.     

不同焊接条件下接头组织和断裂韧度的对比分析

在球阀的焊接过程中采用振动埋弧焊和常规埋弧焊相结合的工艺.接头金相显示,附加振动后,焊接接头晶粒细化明显,熔合区和过热区变窄,魏氏组织减小.从断裂力学的角度分析机械振动对焊接接头韧度的影响,结果表明,焊缝的断裂韧度明显大于HAZ;振动焊接条件下的焊缝和HAZ的CTOD值明显高于常规焊接下焊缝和HAZ的CTOD值;且振动焊接使得焊接接头的各部分之间断裂韧度的差别明显缩小,断裂韧度更趋均匀化.经断口的扫描电镜可观察到振动焊接下焊缝的韧窝密度明显大于常规焊接下焊缝的韧窝密度.     

Joint strength and behaviour of coated aluminium in laser lap welding of steel sheets

When galvanized steel sheets are closely overlapped and welded by laser lap welding, a large amount of molten metal spatters, resulting in a poor surface appearance of the weld and weakened strength of the welded joint, as compared with that of cold-rolled steel sheets. Whereas in the case of aluminium-coated steel sheets, even when they are closely overlapped and welded by laser lap welding, no spattering occurs. Thus, a good surface appearance of the weld is obtained, but the welded joint has lower strength. In both the mentioned cases, it is known that if a clearance of about 0.1 mm is provided between the steel sheets, laser lap welding produces a good surface appearance of the weld and the welded joint strength equal to that of the cold-rolled steel sheets. This report discusses specifically how, in laser lap welding of overlapped Al-coated steel sheets, Al of the coated layer comes to enter the weld metal, also specifically how to reduce the joint strength, as well as what behaviours of Al are present when a clearance is provided between the steel sheets. When the steel sheets are closely overlapped and welded, Al becoming molten on the base metal side of the bond of the overlapped face becomes swallowed up by the bath streams of the molten pool, flowing into the molten pool, then forming the Fe–Al intermetallic compound, while not being sufficiently stirred. It is considered that when subjected to the tensile shear test, the Fe–Al intermetallic compound starts to fracture, thereby causing a partial loss of the weld metal and a reduction in the joint strength. On the other hand, when a clearance is provided between the steel sheets, it may be inferred that the fusion Al on the base metal side of the bond stays in place without flowing into the molten pool, consequently not forming the Fe–Al intermetallic compounds within the weld metal.     

7A52铝合金搅拌摩擦焊焊缝的组织分析

通过对7A52铝合金进行大量的搅拌摩擦焊接试验,对焊缝的宏观组织、微观组织及显微硬度进行分析.焊缝可分为热影响区、热机影响区和焊核等三个区域.其中,焊核为明显的再结晶等轴晶粒,晶粒明显细化;热机影响区出现了晶粒粗化现象,由母材的细纤维组织变形为具有一定弧度的弯曲粗纤维组织;热影响区的晶粒与母材相似,但出现了晶粒粗化现象.沿焊缝横截面的显微硬度的分布呈高-低-高-低-高的趋势,其中焊缝顶部的硬度达到了母材的硬度,硬度最低处位于前进侧的热影响区区域.     

薄板TC4钛合金TIG电弧和激光焊接接头晶粒尺寸与微观组织

对薄板TC4钛合金进行TIG电弧和激光焊接技术研究,重点分析了TIG焊接电流、焊接速度和激光输出功率对TC4钛合金焊接接头晶粒尺寸、微观组织和显微硬度的影响规律. 试验结果表明,在实现薄板TC4钛合金完全熔透的条件下,激光焊接具有更小热输入,接头焊缝区和热影响区宽度也显著降低. TIG焊接接头晶粒尺寸随热输入增加,呈现增加趋势. 随距焊缝中心位置增加,焊接接头晶粒尺寸均逐渐降低. TC4钛合金激光焊接接头焊缝区呈现魏氏组织特征,针状α'马氏体细小. 近缝热影响区组织为网篮状α'马氏体,而近母材热影响区为未转变α相和针状α'马氏体的双相组织. 随距焊缝中心位置增加,马氏体生成量逐渐减少,焊缝显微硬度值呈现降低趋势;同时相比于TIG焊接,TC4激光焊接接头具有更高的显微硬度.