高锰低磁钢钢结构焊接修复工艺

低磁钢是一种特殊用钢,本文在对其进行焊接性分析基础上,采取特殊焊接工艺,成功地进行了一座被损金属结构物焊接和裂纹焊补。     

快速凝固耐热铝合金焊接技术的研究现状

阐述了快速凝固耐热铝合金焊接研究现状,分析了快速凝固耐热铝合金的焊接性,讨论了钨极氩弧焊、电容放电焊、电子束焊、激光焊、摩擦焊以及钎焊在快速凝固耐热铝合金材料连接中的应用和存在的问题,指出具有高能量密度、低能量输入的电子束焊、激光焊以及摩擦焊适于快速凝固耐热铝合金的焊接.     

钛及钛合金搅拌摩擦焊研究进展

搅拌摩擦焊技术已经成功应用于铝合金等低熔点材料的焊接,但针对钛及钛合金等高熔点材料的研究仍在进行之中。从焊具设计、接头显微组织与力学性能和焊接过程仿真等方面综述了钛及钛合金搅拌摩擦焊国内外研究进展,为搅拌摩擦焊技术应用于钛及钛合金提供参考。     

搅拌摩擦焊接技术基础及其工程应用

搅拌摩擦焊(FSW)是最近十几年才发展起来的一项新的连接技术,焊接的材料非常广泛.在焊接时材料不熔化,减少和消除了因金属熔化带来的冶金反应的复杂性,因此特别适合焊接活性金属或两种物理和化学性质相差悬殊的材料.利用搅拌摩擦焊技术,已对高温活性金属、低熔点金属、复合材料、异种金属或合金等材料进行了焊接性能实验研究和工程应用研究,对核工业使用的铍-铝合金、铜合金核废物容器箱体也进行了焊接.利用摩擦搅拌技术还能细化金属材料的晶粒和增强硬度.     

焊接技术在航空航天工业中的应用

焊接技术是航空航天工业的重要连接技术,在航空航天材料加工过程中,处于重要地位,焊接技术已成为飞机制造中的关键技术,为飞机的设计和制造提供了技术保证。本文对电子束焊、激光焊、搅拌摩擦焊、线性摩擦焊、扩散焊的原理、特点及应用进行了介绍。     

钛合金搅拌摩擦焊研究现状

搅拌摩擦焊是目前钛合金焊接技术研究的热点.从搅拌头材料与结构设计、焊接工艺与组织性能关系、焊接过程数值仿真等方面综述了钛合金搅拌摩擦焊国内外研究现状.以现有的研究结果来看,搅拌摩擦焊是实现钛合金高强可靠连接的有效途径,选择合适的焊接参数和焊后热处理工艺可获得高质量钛合金焊接接头;但由于对钛合金用高温高强高耐磨搅拌头研制...     

35CrMo调质钢的焊接工艺确定

本文针对35crmo钢的焊接工艺特点进行了详细的分析,选择了合适的焊接材料,焊接工艺和焊后热处理措施,采用氩电联焊的方法对φ76×9mm 35crmo钢管进行焊接,并进行了焊接工艺评定,并取得了良好的焊接效果。     

有色合金A-TIG焊研究现状

活性化TIG焊(A-TIG焊)可以用于焊接不锈钢、碳钢、铝合金、镁合金、钛合金和镍基合金等材料。根据国内外关于A-TIG焊接技术研究、发展及应用的实际情况,综合论述了A-TIG焊接技术这一新型焊接方法在铝合金、镁合金、钛合金和镍基合金焊接领域中的研究现状。     

等离子-MIG焊在有色金属焊接中的应用研究现状及展望

随着复合焊接成为焊接领域的热点,等离子-MIG焊作为一种高能量束流的焊接方法得到了广泛的研究,等离子-MIG焊具备阴极雾化的功能,有利于清理金属表面的氧化膜,对有色金属焊接有独特的优势。介绍了同轴式和旁轴式等离子-MIG焊的工作原理及优缺点,从数值模拟、控制与监测方法、工艺参数研究3个方面对等离子-MIG焊在有色金属焊接中的应用研究现状进行了分析。分析结果表明,等离子-MIG焊在铝合金材料焊接中研究进展显著,已经能够实现高质量的焊接,并开展了在镁、铜等其他有色金属焊接方面的研究,取得了一定的效果。最后对等离子-MIG焊的应用前景和发展方向进行了展望,等离子MIG焊在双电弧耦合机理、多物理场的协同工作、系统稳定性等方面还有待深入研究。     

熔化极气体保护焊在变压器油箱及零部件焊接中的应用分析

不管在变压器设计或工艺技术等方面,都会采用到焊接技术,但是有的焊接所用材料过于细小或焊接部位太过"偏僻’,这对焊接来说是个很大的问题,但随着大型变压器各项技术的逐步完善,经过大量的焊接工艺试验多年的实践,找到了变压器油箱材料焊接办法——熔化极气体保护焊。本文通过对熔化极气体保护焊的认识,分析熔化极保护焊在变压器油箱及零部件的应用。     

ZG 1Mn19Ni3Al 铸焊结构低温性能研究

通过化学成分设计和金相组织设计，开发了一种适用于与１６Ｍｎ钢组成铸焊结构的新铸钢ＺＧ１Ｍｎ１９Ｎｉ３Ａｌ。研究了这两种材料组成的焊板在常温、低温（－１９６℃）下的力学性能和冲击断口形貌。试验结果表明，夹杂物和焊接线能量对其低温冲击韧性有着显著的影响。具有γ＋ε双相组织的ＺＧ１Ｍｎ１９Ｎｉ３Ａｌ钢用于低温（－１９６℃）铸焊结构中时要注意钢水精炼和采用适当的焊接线能量     

耐磨耐蚀Ni-Al金属间化合物基复合保护层的研制

用粉末冶金法制备WC／Ni3Al复合材料焊条，堆焊于1Cr25Ni20耐热钢的表面，获得的复合材料的耐磨粒磨损性能是45钢的3倍以上，耐硫化腐蚀性高于1Cr25Ni20耐热钢1倍，高于钴基合金Stellite6约50％，用其制作火电厂燃烧室的喷口钝体，使用寿命较原8Cr26Ni4Mn3大幅度提高，可达到8个月以上。     

Gap-free fibre laser welding of Zn-coated steel on Al alloy for light-weight automotive applications

As a result of new policies related to global warming announced by the European Union, avoiding unnecessary energy waste and reducing environmental pollution levels are becoming a major issue in the automotive industry. Accordingly, the lap welding of Zn-coated steels process, which is commonly used for producing car doors, has been gradually developed to lap welding of Zn-coated steel to light materials, such as Al alloy, Mg alloy and composite materials, in order to effectively reduce the vehicle weight. In certain part of car manufacture, organic glues are used to temporally join the Zn-coated steels and Al alloys before permanent welding takes place. The stability of such temporary joining by glues needs improving. Laser “stitching” or low strength welding could be considered as an alternative. However, challenges exist in joining Zn-coated steel on Al alloy by laser welding, due to significant differences of material properties between the two welding materials. Porosity, spatter and intermetallic brittle phases are readily produced in the weld. In this study, the effects of welding speed, laser power, number of the welding passes and type of shielding gas in gap-free welding of Zn-coated steel on Al alloy were investigated using a 1 kW single mode continuous wave fibre laser. Results show that a weld with higher shear strengths in the laser stitching application and less intermetallic phases could be obtained when nitrogen gas was used as the shielding gas. The corrosion resistance and the surface finish of the weld could be improved in double pass welding, especially when argon gas was used as the shielding gas.     

Interfacial bonding mechanism in Al/coated steel dissimilar refill friction stir spot welds

Defect-free dissimilar Al/zinc coated steel and Al/AlSi coated steel welds were successfully fabricated by refill friction stir spot welding. However, Al alloy and uncoated steel could not be welded under the same welding condition. Al-Zn eutectic layer formed at the Al/zinc coated steel interface showed non-uniformity in thickness and nanoscale intermetallic (IMC) produced was discontinuous. The bonding formation between the Al-Zn layer and the surrounding materials was attributed to a liquid/solid reaction mechanism. Bonding formation at Al alloy and AlSi coated steel interface was attributed to a solid/solid reaction mechanism, as the joining process did not involve with melting of base metals or AlSi coating materials. Kissing bond formed at the weld boundary acted as a crack initiation and propagation site, and the present study showed that weld strength of Al 5754/AlSi coated steel was greatly influenced by properties of original IMC layer.     

超低碳焊条钢的VOD冶炼

设计的初炼炉出钢成分(w,%)为:C0.70～0.90;Mn、Si0.20～0.30;Al0.010～0.020,出钢温度为1660～1680℃,为VOD精炼超低碳焊条钢提供了足够的热能。初炼炉热装50%铁水,采用氧化法冶炼能有效控制砷、铜、磷、铬、钒等微量元素的含量;VOD精炼过程中通过工艺手段获取"玻璃"渣是控制碳、氧、氮、铝、硅、锰等元素含量行之有效的方法。制定的EAF+VOD冶炼工艺保证了生产的焊条钢各项指标均满足技术要求,质量达到国际同类产品的水平。     

WC颗粒在堆焊过程中溶解机理的研究

研究了WC／Ni3Al表面强化功能复合材料的制备及WC颗粒的溶解机理。在堆焊过程中，WC／Ni3Al复合材料焊条中的WC直接溶解进入基体中，然后析出W2C，而非WC分解成W2C然后溶解。当焊条中含5％(质量分数)WC时，部分Al被氧化，WC溶解，析出W2C，形成碳化物包裹氧化物的球形复合析出物，基体转化成Nb(AlTi)C，形成碳化物包裹氧化物／金属间化合物的复合材料。随着WC含量增加，Al氧化减少。当焊条中的WC含量达到30％时，焊层中的Al不被氧化，表面层中的大部分WC颗粒溶解，析出针状W2C，形成碳化物／金属间化合物复合材料，耐磨性可达45钢的3倍以上。     

中厚板低合金钢Q345R埋弧焊接工艺研究

研究了Q345R低合金钢H10Mn2焊丝和SJ101焊剂焊接工艺,结果表明,焊接接头抗拉强度达到517MPa,大于母材最低值490 MPa,-20℃V型低温冲击功吸收值最小值98 J,高于最低要求41 J;焊接接头达到NB/T 47013.2-2011能标Ⅰ级要求,选择的焊接材料和制定的焊接工艺满足Q345R中厚板低合...     

Cr7C3 / Ni3Al 复合材料制备过程中碳化铬的溶解再析出行为

将真空常压烧结方法制得的Cr₃C₂-Ni₂Al 复合焊丝堆焊于碳钢表面。分析表明, 在堆焊过程中, 利用氩弧物理热和Ni-Al 反应热, Ni 与Al 化合反应生成Ni₃Al 金属间化合物, Cr₃C₂ 则发生分解, 除少部分[ C]与[Cr ]固溶于Ni₃Al 基体中外, 大部分反应析出更稳定的Cr₇C₃ 相, 其尺寸取决于堆焊层中不同区域的冷却环境,较为均匀地分布于Ni₃Al 基体中。由于Cr 在Ni₃Al 中的固溶度远大于C , 加之Cr₃C₂ 转化为Cr₇C₃ 也造成部分富余的C , 结果造成在该Ni₃Al 表面强化材料焊层中形成石墨相, 其密度轻、熔点高, 主要偏聚于焊层表层。Cr₇C₃ / Ni₃Al 复合材料的室温、高温硬度远高于传统高温耐磨材料Stellite 合金, 该材料有望成为一种新型的高温耐磨表面强化材料。      

Microstructure characteristics of thick aluminum alloy plate joints welded by fiber laser

It's difficult to weld high strength thick plate since the groove is huge when using traditional arc welding, and the weld tends to be softened and large deformation could occur after multi-layer welding. All of these can affect the industrial application of high strength thick plate wielding. In this case, developing advanced welding technology and welding material is necessary to optimize the microstructure and performance of the welds. Fiber laser has many advantages such as good monochrome and high quality laser beam. In order to decrease the heat damage to the base metal from the welding heat source, low heat input is employed for welding thick plate. Fiber laser is applied in the welding of 20 mm thick Al–Zn–Mg–Cu alloy with super narrow gap filler wire. The microstructure comparison of Al–Mg–Mn alloy and Al–Mg–Mn–Zr–Er alloy welded joints reveals that a huge amount of fine equiaxed grains is formed in the weld zone of Zr and Er micro-alloying Al–Mg–Mn alloy welding wire and a great number of precipitation strengthening phases are precipitated in the weld zone after the heat treatment of welded joints in the entirety.     

Laser-tungsten inert gas hybrid welding of dissimilar metals AZ31B Mg alloys to Zn coated steel

Laser-tungsten inert gas (TIG) hybrid welding has been developed for joining Mg alloys to Zn coated steel in a lap joint configuration. The joint could not be produced in laser or arc welding only, while acceptable joints without obvious defects were obtained with a relatively wide processing window in the hybrid process. Two reaction layers were observed to form at the interface and were identified as Mg–Zn eutectic structure (α-Mg + MgZn) and Fe₃Al phase by TEM analysis. In some cases, Al₆Mn phase also formed adjacent to the Fe–Al reaction layer. The tensile-shear strength attained the maximum value of 68 MPa, representing 52.3% joint efficiency relative to Mg base metal. The element Al from AZ31B Mg alloys diffused to the liquid/solid interface and then reacted with the elements from steel, such as Fe and Mn, contributing to the metallurgical bonding at the interface. The weak bonding between Mg–Zn reaction layer and newly formed Fe–Al layer resulted in the interfacial failure.