Nd:YAG激光焊接800 MPa TRIP钢的接头组织与性能

采用Nd:YAG激光对强度为800MPa,厚度为1.2mm的TRIP钢板进行焊接.研究焊接速度对焊缝外观和截面成形的影响及接头的组织特点、硬度、强度和成形能力.激光功率相同,焊接速度较低时焊缝易产生气孔,速度较高时易发生飞溅;焊接速度对焊缝熔深及熔宽也有影响.焊缝组织主要由马氏体构成,从焊缝、热影响区到母材,组织中马氏体含量下降,接头的最高硬度出现在焊缝或热影响区.在平行于焊缝方向,焊接接头的抗拉强度高于母材,垂直于焊缝方向,接头的抗拉强度与母材相当.由于焊缝中出现马氏体,接头的塑性和韧性降低,板材的冲压成形能力下降.     

CO_2激光焊接600MPa DP钢接头组织与性能

采用CO2激光对抗拉强度为600MPa,厚度1.4mm的DP钢进行焊接.研究焊接速度对焊缝外观和截面成形的影响、接头的组织特点、硬度、强度和成形能力.结果表明,激光功率相同,焊接速度较低时焊缝易产生气孔,焊接速度较高时易发生飞溅;焊接速度对焊缝熔深及熔宽也有影响.焊缝区组织主要由马氏体构成,从焊缝、焊接热影响区到母材,组织中马氏体含量下降,接头的最高硬度出现在焊缝或热影响区.在平行于焊缝方向,焊接接头的抗拉强度高于母材,垂直于焊缝方向,接头的抗拉强度与母材相当.由于焊缝出现马氏体组织,接头的塑性和韧性降低,板材的冲压成形能力下降.     

2219-T651铝合金激光摆动焊接接头微观组织和力学性能

采用激光摆动焊接技术对2219-T651铝合金进行了不同摆动幅度和频率下的焊接试验,研究了摆动工艺参数、焊缝气孔率和宏观成形、接头组织和性能之间的内在联系.结果表明,与无摆动焊接相比,激光摆动焊接可以降低焊缝气孔率,尤其随着摆动幅度的增加,当摆动幅度为2.5 mm时,气孔率降至1.66%.与母材相比,热影响区和熔化区发生软化.靠近焊缝的热影响区,由于沉淀强化作用的变弱,硬度逐渐降低,直至出现“平台”.而由α(Al)基体以及枝晶间和晶界α(Al)+θ(Al₂Cu)共晶相组成的熔化区,因铜的偏析导致固溶强化效果被削弱,表现出最低的硬度.此外,部分摆动参数下焊缝晶粒尺寸有所细化,这引起了其硬度的略微升高.当摆动频率为150 Hz和摆动幅度为2.5 mm时,接头的抗拉强度高达318 MPa,约为母材抗拉强度的69.4%,接头抗拉强度与断口孔洞面积占比呈线性负相关关系,焊缝气孔率是影响焊态接头抗拉强度的主要因素.     

Characteristics of Nd： YAG laser welded 600 MPa grade TRIP steel

Microstructures and mechanical properties of Nd: YAG laser welded transformation induced plasticity (TRIP) steel with tensile strength of 645 MPa were studied. Due to high cooling speed of laser welding, the weld metal mainly consists of martensite different from the base metal, which is composed of ferrite matrix with bainite and a little retained austenite. Therefore, the weld metal has maximum hardness at welded joint. The yield strength and tensile strength of welded specimens tested perpendicular to weld line were almost equal to those of the base metal. But the yield strength and tensile strength of welded specimens tested parallel with weld line were a little higher than those of the base metal. The formability of laser welded TRIP steel was decreased compared with that of the base metal.     

激光焊接HR-2抗氢不锈钢的性能及组织

为研究HR-2抗氢不锈钢的激光焊接性,对焊接接头的力学性能、试样断口扫描电镜形貌、焊缝金相组织及焊缝内气孔的形貌与成分进行了试验与分析.结果表明,激光焊接HR-2抗氢不锈钢,虽然焊接接头的抗拉强度有所升高,断面收缩率和缺口冲击韧性值有所降低,但试样的微观断裂机制与母材一样是按微坑聚集型的韧性断裂方式进行的,表明焊接接头仍然具有较好的韧塑性;焊缝中未出现明显的合金元素烧损或过多的氧化及脱氧产物,焊缝热影响区很窄,与基体的结合界面良好;激光深熔焊接HR-2抗氢不锈钢,焊缝中除了容易出现常见的析出性气孔和反应性气孔外,更容易出现激光焊接所特有的小孔型气孔.     

0Cr15Ni5Cu4Nb中厚板锁底结构大功率光纤激光焊接工艺特性

采用大功率光纤激光对7 mm厚度0Cr15Ni5Cu4Nb不锈钢锁底结构实施了焊接试验,通过对不同焊接工艺参数下的接头质量、力学性能、微观组织结构的分析,研究了其焊接工艺特性. 结果表明,焊缝中的主要缺陷是焊接气孔,采用负离焦、高速度的焊接参数能够有效抑制气孔的形成. 焊缝区域硬度有所增加,并且焊缝上部和下部的硬度要高于中部的硬度值,接头的力学性能稳定,焊缝平均抗拉强度为970 MPa,冲击韧性略有降低,为母材的89%. 焊缝组织主要由马氏体、残余奥氏体和δ-Fe组成,焊缝中部δ-Fe要多于上部,马氏体转变不充分,热影响区中主要由晶粒细小的淬火马氏体组成.     

活性剂对激光-电弧复合焊接的影响

提出了激光-电弧复合活性焊接法,以提高小功率激光-电弧复合焊接的熔深.在待焊不锈钢表面涂覆一层活性剂,然后进行激光-电弧复合焊接.研究了工艺参数对焊缝成形性的影响,并对焊接接头的组织性能进行了分析.结果表明,涂覆活性剂后可以使复合焊接的熔深增加,并且可以细化复合焊焊缝组织.复合焊接头与复合活性焊接头的显微硬度变化规律一致.复合活性焊接头的抗拉强度较高,达到母材抗拉强度的92%.复合活性焊接头的腐蚀速率低于复合焊接头的腐蚀速率,具有良好的耐蚀性能.     

AZ31B镁合金熔化极气体保护焊焊缝的组织和力学性能(英文)

使用熔化极气体保护焊对变形镁合金板材对接。在不同焊接工艺参数下观察焊缝中的气孔特征,分析气孔成因以及气孔对接头微观组织和力学性能的影响。显微组织检测结果表明:气孔主要分布在焊缝顶部或底部,而且气孔能相互连接甚至产生裂纹。然而,在合适的焊接工艺参数下,气孔的产生可以得到有效控制。拉伸测试结果表明:接头的平均抗拉强度接近甚至高于母材。由于第二相β-Mg17(Al,Zn)12的强化作用,焊缝区的硬度高于母材。     

固溶处理对选区激光熔化AlSi10Mg合金激光焊孔隙缺陷的影响

针对选区激光熔化成形AlSi10Mg铝合金焊接过程中氢气孔敏感性高的问题,采用固溶脱氢与真空固溶脱氢的方法对比了脱氢处理对合金激光焊接接头孔隙缺陷的影响,分析了不同状态下激光焊焊缝气孔分布、组织演变及力学行为。结果表明,固溶处理能够有效减少选区激光熔化成形AlSi10Mg铝合金激光焊焊缝气孔率,且真空固溶处理效果最好,气孔率从沉积态激光焊接焊缝的2.64%降到真空固溶态焊缝的0.14%;通过对接头组织的演变与基板物相形态、成分的变化分析阐述了孔隙出现的原因,揭示了真空热处理是解决由于基板中预先存在的较高含量的氢导致焊缝氢气孔形成的有效方法。固溶后母材硬度明显下降,各试板焊缝的平均硬度为80HV,较为一致;固溶态试板焊接接头抗拉强度为143MPa,低于沉积态接头,但延伸率增加到了24%,表现为韧性断裂特征。     

工业纯钛光纤激光-MIG复合焊接工艺及性能

采用光纤激光与熔化极惰性气体保护电弧焊(MIG焊)复合焊接工业纯钛,分别对激光焊、MIG焊和复合焊接头的焊缝表面成形、横断面进行了观察,并进行了激光焊和复合焊接头的拉伸试验及杯突试验.结果表明,复合焊的电弧稳定性比MIG焊显著提高,焊接速度可提高7倍;复合焊与激光焊接头的抗拉强度高于母材;复合焊接头的杯突值优于激光焊接头的杯突值,这是因为复合焊焊缝的微观组织有利于接头的塑性.因此,采用光纤激光-MIG电弧复合焊接方法很好地实现了工业纯钛的高速焊接,焊缝成形良好,接头的塑性优于单一激光焊的塑性.

Abstract：

Fiber laser-metal inert gas (MIG) arc hybrid welding was used to weld the commercial pure titanium (CP-Ti). The weld appearance, cross section, tensile strength, Erichsen value and microstructure of the CP-Ti welded joints were studied. The results show that the arc stability is substantially improved and the welding speed can be increased to 7 times by fiber laser-MIG hybrid welding. The welded joints by laser welding and the hybrid welding exhibit the higher ultimate tensile strength than those of the base metal. In addition, the welded joint by the fiber laser-MIG hybrid welding has higher Erichsen values than that by laser joints. The difference in plasticity is attributed to the microstructure changes in the welded joint of hybrid welding. Thus, the fiber laser-MIG hybrid welding of CP-Ti can be carried out suecessfully at higher welding speed with a good combination of weld bead appearance and plasticity.     

921A钢激光-MAG复合焊接头组织及性能

针对6 mm厚的921A钢板,采用激光-MAG复合焊接工艺进行对接焊试验,并对焊接接头的显微组织、硬度、拉伸性能、耐腐蚀性能等进行了分析。结果表明,采用激光-MAG复合焊工艺可获得成形连续美观的焊接接头,无未熔合、裂纹、气孔等缺陷;焊缝组织为针状铁素体、少量沿晶界析出的先共析铁素体及长条状贝氏体,热影响区组织为马氏体;焊接接头的拉伸性能和冲击性能均符合国家标准要求,焊缝强度高于母材,但塑韧性低于母材。峰值硬度在热影响区,为315 HV,焊缝硬度约为280 HV,符合最高硬度不得超过410 HV的规定。焊缝耐电化学腐蚀性能最强,母材次之,热影响区最低;激光和MAG电弧2种热源共同作用区域的组织分布更加均匀,硬度及耐腐蚀性能较激光单独作用区域有了明显改善。 创新点： 采用激光-MAG复合焊实现了6 mm厚度921A钢板无缺陷对接焊的一次焊接成形。焊缝晶粒更加细化,分布更加均匀;焊缝抗拉强度、硬度、电化学腐蚀性能均高于母材,冲击吸收能量满足船级社要求。     

一种针对低匹配焊接接头的"等承载"设计方法

为提高高强钢低匹配接头承载能力,提出了低匹配接头与母材具有相等的静载承载能力和疲劳抗力的"等承载能力"(ELCC)概念.从安全性角度出发,焊接结构必须同时具有足够的强度和应力松弛能力,而强度失配接头的断裂模式类型能够同时反映接头的强度、塑性变形能力以及焊缝与母材之间塑性变形的非均匀程度.母材先于焊缝发生塑性变形的全面屈...     

镁合金激光氩弧复合热源冷填丝焊接工艺

研究了镁合金的低功率激光-氩弧复合热源冷填丝焊接工艺.通过5 mm厚镁合金板材的堆焊试验,研究了焊接电流、焊接速度、钨极高度和热源距离等参数对焊缝成形和焊接熔深的影响,确定了钨极高度为0.75 mm,热源间距DLA为1.2 mm左右的焊接参数范围;在堆焊基础上,进行了2.5 mm厚镁合金板材的对焊试验,实现了单面焊双面成形,焊接速度达1 200 mm/min,焊接接头熔深为单TIG冷填丝接头熔深的两倍,抗拉强度达到母材的95%左右,实现了高速、优质的镁合金冷填丝焊接.另外,简要分析了激光的加入对焊接过程的影响.     

工艺参数对SiCp/101Al复合材料电子束焊接头的影响

以SiCp/101Al复合材料为研究对象,采用真空电子束焊接技术,研究在不同工艺参数条件下获得接头的组织与性能.通过拉伸试验,研究不同工艺参数对获得接头力学性能的影响;利用光学显微镜观察分析不同参数条件下接头区域的金相组织;采用透射电镜观察SiC-A1界面微观结构;利用扫描电镜观察接头断口形貌;利用X射线衍射仪测定接头焊缝区的相结构.结果表明,在保证试件完全焊透的情况下,降低电子束的线能量,可在一定程度上提高接头的强度;接头中的气孔主要形成于熔合线区域,快速焊接和电子束扫描可使气孔形成受到大大抑制;进一步的修饰焊有利于提高焊接接头的质量.     

Tensile Properties and Fusion Zone Hardening for GMAW and MIEA Welds of a 7075-T651 Aluminum Alloy

Tensile and hardness values for 7075-T651 aluminum alloy in the as welded and post weld heat treated conditions（solubilization and artificial aging-T6）,obtained using GMAW and modified indirect electric arc（MIEA）welding processes are presented.Results showed that the base material along rolling direction exhibited a tensile strength of around 600 MPa and elongation of 11%.For the as welded condition,tensile strength was 260 MPa and elongation percent of 3%.This behavior was attributed to brittleness induced by the microstructural characteristics of the welded alloys,as well as high porosity.Hardness profiles along the welds were obtained and different welded zones were identified.A soft zone（＊100 HV0.1） in the heat affected zone for GMAW and MIEA was observed,the minimum hardness corresponding to weld metal（＊85 and ＊96 HV0.1for GMAW and MIEA,respectively）.The high dilution between filler and base metal during welding in MIEA allows to the Zn and Cu to flow from the base metal into the weld metal,inducing hardening by solution and subsequent artificial aging.In this regard,the hardness of the weld metal for MIEA increases by 56%,while the tensile strength reaches a value close to 400 MPa.For GMAW,non-favorable hardening effect was observed for the weld metal after solution and artificial aging.     

铝合金同轴式等离子-MIG焊接工艺

使用同轴式等离子-MIG焊枪,对防锈铝LF5进行工艺试验,研究其工艺参数对焊缝成形及组织的影响,并检验了组织中的缺陷.结果表明,同轴式等离子-MIG焊接铝合金时能够获得较为理想的焊缝;与偏置式等离子-MIG焊接低碳钢相比,用同轴等离子-MIG焊接铝合金时等离子电流的增加对焊缝影响更大,而对熔宽的影响相对较小;焊接过程中,焊丝与母材在高温时熔敷共同形成焊缝中过渡;等离子弧清理范围变小,易形成氧化物夹渣.     

10Ni3CrMoV钢CO2激光多层焊的接头组织与性能

与传统电弧焊相比,激光焊接厚板优势明显。采用纯激光焊和激光电弧复合焊等多道焊接技术实现了28 mm厚10Ni3CrMoV钢的高效焊接,采用光学显微镜分析焊缝、热影响区和焊缝重叠区的组织,激光复合焊缝组织主要为针状铁素体,纯激光焊缝、粗晶区和细晶区组织主要为板条马氏体,激光复合焊缝重叠区组织为粒状贝氏体+马氏体,纯激光焊缝和激光复合焊缝重叠区组织为马氏体+少量粒状贝氏体。测试了焊接接头的力学性能,结果表明,激光复合焊缝金属的冲击韧性较高,焊接接头的抗拉强度和屈服强度与母材相当,延伸率略小于母材,焊接接头的最大硬度小于360 HV,弯曲性能合格。     

Microstructure and Microhardness of Laser Beam Welded Al-Mg-Mn-Zr-Er Joint

In this work,the weldability of the alloy Al-Mg-Mn-Zr-Er with high power Nd:YAG laser has been studied.Samples were subjected to three different welding heat inputs to obtain various weld beads.The main objective of the present work has been to investigate the change of microstructure and microhardness at the Al-Mg-Mn-Zr-Er laser weld beads.Results showed that the top width of the bead was larger at the higher laser power.Grain structure refinement was found in welded metal,especially at higher laser power.It was also verified that the microhardness of weld bead was raised with the decrease of laser power,due to the microstructure refinement at the condition of lower laser power.     

Laser welding of high-strength aluminium–lithium alloys with a filler wire

The possibilities of using laser welding with a filler wire for joining sheet materials made of V-1469 and V-1461 high-strength aluminium–lithium alloys are investigated. The optimum conditions of placing the filler wire in relation to the laser beam in the weld pool are determined. The optimum welding parameters resulting in the high-quality formation of the welded joint with equal sagging and excess metal and the absence of porosity and cracks are also determined. The mechanical properties of welded joints are outlined and the microstructure of the welded joint is investigated. The corrosion resistance of the produced welded joints is studied.     

高强钢CO2激光-MAG复合焊接性能

为了研究CO₂激光-熔化极活性气体保护焊（MAG）复合焊接性能,采用CO₂激光和CO₂激光-MAG复合焊接590MPa级高强度钢,对其焊接接头的显微组织和力学性能进行了研究.结果表明,激光-MAG复合焊接的焊缝金属中,MAG电弧作用区主要为珠光体和贝氏体,激光作用区主要为马氏体;激光-MAG复合焊接的焊缝金属中Mo和Mn合金元素的分布具有不均匀性;激光和激光-MAG复合焊接的试件焊接接头拉伸性能完全满足要求,焊缝强度高于基体强度;激光-电弧复合焊缝金属在-60℃～+15℃试验温度范围内的冲击韧性比激光焊缝金属高;激光-MAG复合焊接焊缝金属硬度在250～400 HV之间,高于基体金属的硬度.