Theoretical Investigation of Calculating Temperatures in the Combining Zone of Cu/Fe Composite Plate Jointed by Explosive Welding

The heat-transfer behavior of the interface of Flyer plate (or Base Plate) has great influence on the microcosmic structures, stress distributions, and interface distortion of the welded interface of composite plates by explosive welding. In this paper, the temperature distributions in the combing zone are studied for the case of Cu/Fe composite plate jointed by explosive welding near the lower limit of explosive welding. The results show that Flyer plate (Cu plate) and Base Plate (Fe plate) firstly almost have the same melting rate in the explosive welding process. Then, the melting rate of Cu plate becomes higher than that of Fe plate. Finally, the melt thicknesses of Cu plate and Fe plate trend to be different constants, respectively. Meanwhile, the melting layer of Cu plate is thicker than that of Fe plate. The research could supply some theoretical foundations for calculating the temperature distribution and optimizing the explosive welding parameters of Cu/Fe composite plate to some extent.     

CuNiMn/30CrMnSi整体材料界面过渡层的研究

研究了CuNiMn／30CrMnSi整体材料界面过渡层的溶化过程。通过设计和控制不同的CuNiMn／30CrMnSi整体材料界面过渡层，获得了比CuNiMn合金本体强度更高的界面结合强度。文中也分析了界面过渡层的成分与微观结构。     

Al0.1CoCrFeNi高熵合金/TA2钛复合板爆炸焊接试验及性能测试

高熵合金是一种新兴的多主元合金,具有作为结构材料的潜力,但对高熵合金焊接工艺的研究还很有限. 通过爆炸焊接实现了Al_0.1CoCrFeNi高熵合金与TA2工业纯钛的复合连接,并研究了Al_0.1CoCrFeNi/TA2复合板的微观结构和力学性能. 结果表明,Al_0.1CoCrFeNi/TA2复合板具有不连续熔化区的波状结合界面,熔化区中呈现多元素混合状态,并且具有较均匀的元素分布. 熔化区的硬度大于界面附近的硬度,并且硬度随着离界面距离的增加逐渐降低,但仍高于原始材料. 相对于焊接前的Al_0.1CoCrFeNi高熵合金的强度(398 MPa),爆炸焊接后的Al_0.1CoCrFeNi/TA2复合板强度明显提高(567 MPa),但断后伸长率降低. 说明爆炸焊接可以有效的将Al_0.1CoCrFeNi高熵合金与TA2工业纯钛相结合,而形成的复合板具有良好的力学性能.     

Mechanical evaluation and thermal modelling of friction welding of mild steel and aluminium

In friction welding of two dissimilar materials, two rods are welded together by holding one of them still while rotating the other under the influence of an axial load which creates frictional heat in the interface. In this study, mechanical properties of mild steel and aluminium welded rods were evaluated to understand the thermal effects, and an explicit one-dimensional finite difference method was used to approximate the heating and cooling temperature distribution of the joint. The thermal effects of the friction welding were observed to have lowered the welded materials hardness compared to the parent materials. The tensile strength of the welded rods is lower than the parent rods due to incomplete welding. The preliminary predictions were compared to actual thermocouple data from welds conducted under identical conditions and were shown to be in fair agreement. The finite difference method proposed in this work will provide guidance in weld parameter development and will allow better understanding of the friction welding process.     

YG30硬质合金与因瓦合金TIG焊接头的组织与硬度的分析研究

本文选用不同厚度的Ni-Fe、Ni-Fe-C-Mn-Nb因瓦合金,与YG30在不加填充材料、对接条件下直接进行TIG焊接试验,运用光学显微镜、扫描电镜、显微硬度仪等对焊接接头的显微组织和硬度进行研究分析。结果表明,Ni-Fe因瓦合金与YG30连接,在YG30/因瓦合金焊接接头界面区硬质合金侧形成η-碳化物;Ni-Fe-C-Mn-Nb因瓦合金与YG30连接,在界面区没有η-碳化物形成。不同厚度、不同工艺参数的焊接接头中,厚度为2mm、电流为135A和厚度为4mm、电流为145A的两种焊接接头组织均匀,界面冶金结合良好,硬度分布过渡平缓。     

AZ31Mg/2A12Al爆炸复合板界面组织与性能

镁合金板上复合铝合金板对拓宽镁合金的使用范围具有重要意义.?采用爆炸焊接进行了镁合金板和铝合金板工艺试验,并制成镁合金和铝合金复合板.?使用光学显微镜、扫描电子显微镜观察焊后复合板结合界面处的微观形貌,分析了界面形成过程.?使用显微硬度计和剪切试验机测量了复合板结合界面处的硬度和抗剪强度.?结果表明,经爆炸焊接后,复合...     

93W与98W粉末冶金材料摩擦焊接头性能及组织分析

为了充分利用93W钨合金和98W钨合金两种粉末冶金材料各自独特性能优势,开发基于这两种钨合金的复合材质是非常必要的.采用自主研制的HSMZ-10型摩擦焊机,利用优选的焊接工艺参数,将93W钨合金和98W钨合金在主轴转速为2 000r/min,摩擦变形量为5 mm,摩擦压力为30 MPa,顶锻压力为60 MPa,摩擦顶锻变形速率为20 mm/s的条件下,通过摩擦焊接方法成功地实现了焊接,并对接头和母材进行了金相组织分析和力学性能检测分析.结果表明,接头力学性能良好,无未焊透等焊接缺陷;93W和98W粉末冶金材料之间无成分均一化现象,焊缝的强度大于母材.     

焊接电流对Ti2AlNb/TC18焊接界面性能及元素扩散的影响

采用真空电子束焊接对Ti2AlNb和TC18合金进行连接,研究了不同焊接电流时焊接界面的性能及元素扩散情况。结果表明:焊接接头在室温和高温下均获得了较高的抗拉强度。采用同一电流焊接时,TC18侧热影响区的显微硬度值高于该合金基体却低于该侧焊缝区,而Ti2AlNb合金侧热影响区的显微硬度值均高于该侧焊缝区和Ti2AlNb合金基体;在28 mA的焊接电流下,焊接界面的整体显微硬度值均较高,这是因为焊接界面形成了含量较多且尺寸较小的α′马氏体和O相,对界面起到了强化作用。在不同的焊接电流下,合金元素均在焊缝和两侧母材交界处存在较大的浓度梯度,其原因是焊缝金属的快速凝固使得各合金元素没有足够的时间和能量进行充分扩散。     

液化天然气储罐用超低温9Ni钢的研究及应用

以真空冶炼 + 电渣重熔二步法制取镍合金焊芯,设计高碱度药皮形成复层梯度型熔渣,并研制出ENiCrMo-6深冷镍合金专用焊条. 对研制焊条熔敷金属和采用ENiCrMo-6型异质材料焊接9Ni钢接头的力学性能进行试验. 借助Acuteye高速摄像技术研究熔滴过渡及熔池流动特性,采用JSM-6360LV型扫描电子显微镜分析复层熔渣结构. 对焊缝和热影响区进行观察和分析以从不同角度探讨低温断裂行为. 结果表明,针对液态镍合金熔滴过渡颗粒粗大、流动性差、焊缝成形困难问题,通过药皮设计形成复层梯度型熔渣可有效解决焊缝成形. 焊缝组织中,抑制奥氏体柱状晶粗化、减小超低温条件下的塑性损伤是保证低温韧性的重要条件. 采用ENiCrMo-6型焊条焊接9Ni钢,其焊态热影响区过热对板条马氏体和逆变奥氏体相的影响并不显著. 通常情况下,焊接加热不致严重降低过热区中板条马氏体间残留逆变奥氏体相,从而对过热薄弱区低温韧性具有组织保证作用.     

ZChSnSb11-6在镀锡合金钢表面扩散连接分析

在原子扩散理论分析基础上,通过热浸镀锡作为扩散过渡层的方法制备了高强界面的ZChSnSb11-6/30CrMnSi复合材料.采用扫描电子显微镜（SEM）,能谱仪（EDS）表征了ZChSnSb11-6在热浸镀锌30CrMnSi钢表面形成的界面过渡区形貌及其元素分布,并对界面硬度和结合强度进行了表征.结果表明,通过热浸镀锡作为中间层的方法可以制备出巴氏合金/钢双金属复合材料;30CrMnSi钢基体与中间层金属锡形成一层互相扩散的过渡区,厚度随镀锡温度的升高而显著增加;过渡区硬度明显高于两侧基体;界面结合强度随镀锡温度的升高逐渐上升,在900℃时结合强度达到60.6 MPa.     

钛/铝/镁爆炸焊复合板波形界面及力学性能

文中提出以薄的铝合金板作为过渡层,采用爆炸焊接技术成功制备钛/铝/镁层状复合材料. 对钛/铝接合界面、铝/镁接合界面及钛/铝/镁爆炸复合板的整体力学性能进行了分析研究. OM和SEM试验结果表明,钛/铝接合界面和铝/镁接合界面均为波状接合界面,在铝/镁界面出现了局部熔化区;钛/铝接合界面为小尺寸波(λ=160 μm,h=26 μm),铝/镁接合界面为大尺寸波(λ=1 740 μm,h=406 μm);拉-剪试验表明,复合板沿着铝/镁接合界面断裂;弯曲性能测试表明,钛板一侧受拉时复合板弯曲强度和塑性均优于镁合金板一侧受拉,断裂始于铝/镁接合界面,最终从镁合金板一侧剪切断裂失效.     

30CrMnSi/Cu/V/TC4电子束焊接试验研究

使用Cu/V中间层实现了30CrMnSi合金钢与TC4钛合金的电子束焊接,探究了接头组织和性能特征.结果表明,通过添加Cu/V过渡层金属可以避免Ti-Fe元素的直接混合反应生成脆硬的金属间化合物.焊缝不同区域分布着不同组分及性能的特征相,靠近钢侧焊缝为偏聚形成的富Fe相与富Cu相,靠近钛侧焊缝在形成Ti-V固溶体的同时...     

Effect of grain size on hot cracking resistance of the HAZ metal of welded joints in creep-resisting alloys

Summary

Al₂O₃/6061 aluminium alloy composite was welded to aluminium alloys (6061‐T6, 5052‐H14, 2017‐T4) using an inertia type friction welding machine to investigate the microstructures and hardness distributions of friction welded joints. Regardless of the aluminium alloys used, finer alumina particles and finer grain structures were observed in the area near the weld interface. And the occurrence of mechanical mixing and moving of alumina particles into a region other than the composite were observed clearly on the weld interface. The distance moved by the alumina particles became greater in the order of the alloys, 6061, 5052 and 2017. A softened area was observed in the heat affected zone of all the aluminium alloys. It was found 30 days after welding that the hardness of the welded joint between the composite alloy and 6061 alloy had not changed significantly, whilst that of the welded joint between the composite alloy and 2017 was observed to have recovered to the previous standard 14 days after welding.     

锆-钛-钢复合板界面损伤机理及表面耐腐蚀性能

运用内聚力模型研究了锆-钛-钢复合板在粘结试验中的界面损伤过程,并利用扫描电子显微镜分析了界面断裂机理。运用正交试验研究了不同热处理工艺条件下的表面耐腐蚀性能,分析了保温温度、保温时间和升降温速率对粘结性能的影响。结果表明,I型裂纹加载下,界面损伤由内壁处开始,并逐渐发展至整个界面。界面整体属于脆性断裂,而波峰与波谷的过渡斜面则为混合断裂。腐蚀试验的塔菲尔极化曲线研究结果表明,锆覆层在HCl溶液中以点腐蚀为主,而在HAc溶液中以均匀腐蚀为主。爆炸焊接后,锆复合板的耐点腐蚀性能低于纯锆材料,并且保温温度越高,保温时间越长,耐腐蚀性能下降越明显。     

Optimizing pulsed current gas tungsten arc welding parameters of AA6061 aluminium alloy using Hooke and Jeeves algorithm

Though the preferred welding process to weld aluminium alloy is frequently constant current gas tungsten arc welding （CCGTAW）, it resulted in grain coarsening at the fusion zone and heat affected zone（HAZ）. Hence, pulsed current gas tungsten arc welding（PCGTAW） was performed, to yield finer fusion zone grains, which leads to higher strength of AA6061 （Al-Mg-Si） aluminium alloy joints. In order to determine the most influential control factors which will yield minimum fusion zone grain size and maximum tensile strength of the joints, the traditional Hooke and Jeeves pattern search method was used. The experiments were carried out based on central composite design with 31 runs and an algorithm was developed to optimize the fusion zone grain size and the tensile strength of pulsed current gas tungsten arc welded AA6061 aluminium alloy joints. The results indicate that the peak current （Ip） and base current （IB） are the most significant parameters, to decide the fusion zone grain size and the tensile strength of the AA6061 aluminum alloy joints.     

稀土元素对新型Al-Mg合金焊接接头组织和性能的影响

研究了Sc,Zr元素对新型Al-Mg合金焊接接头组织和性能的影响。建立了MIG电弧二维数值分析模型,模拟出电弧温度场的分布情况,电弧最高温度超过20 000 K,且温度分布存在较大的温度梯度,说明高温电弧对合金有益元素有一定的烧损作用。采用合金元素不同的焊丝ER5356,ER5B06和ER5B71作为填充材料,对2 mm厚新型Al-Mg合金进行MIG焊接试验,研究高Mg焊丝添加不同稀土元素对焊接性能及组织的影响。结果表明,使用3种焊丝均可获得性能优良的焊接接头,使用ER5B06焊丝的接头力学性能得到一定提升,但焊缝晶粒细化效果不明显;使用复合添加Sc,Zr微量元素的ER5B71焊丝,接头晶粒能够有效细化,力学性能进一步得到提升。3种焊丝中,采用ER5B71焊丝的焊接接头强度最高,焊接系数为83%,焊接接头中起到细化晶粒作用的析出相以Al3(Sc,Zr)为主。同时,无论采用哪种焊丝,焊接热影响区未发生明细的晶粒粗化,说明在母材中加入一定的Sc,Zr微量元素,可提升合金材料抗软化能力,有效抑制热影响区再结晶行为。 创新点： 采用电弧物理数值模拟和进行试验结合的方法,进行研究论证,使研究内容充实,有理论深度,更具说服力;选择具有稀土元素的铝合金和焊丝作为研究对象,对新材料及焊材的研发具有一定指导意义。     

Effect of Initial Hardness on Interfacial Features in Underwater Explosive Welding of Tool Steel SKS3

This paper aims at investigating effects of initial hardness on interfacial features for identical compositional materials under identical welding conditions. Two underwater explosive welding experiments on tool steel SKS3 with copper foil were carried out: one as-received and the other heat-treated. The welding process was simulated using the commercially available software package LS-DYNA. Numerical simulation gave deformation of the flyer/base plate and pressure distribution during the welding process. Microstructure and hardness at interface of the welded metals were evaluated. The results indicate that decreasing impact energy is accompanied by a shift from wavy to linear interface. Moreover, a comparison of the two experiments allows the conclusion that high initial hardness results in a decrease of wavelength and amplitude under identical welding conditions. Hardness profiles of as-received tool steel-copper welding reveal the hardening effect of impact in the vicinity of the interface. However, of interest is that a decrease in hardness was seen in the case of heat-treated martensitic tool steel with copper, fundamentally differing from previous explosive welding research; phase transition is proposed to discuss the relation between the effects of impact and heat, and those of work hardening and softening.     

钛/铝复合板研究进展

将薄层钛合金板与铝合金板结合可以得到具有优异性能的钛/铝复合板,具有广阔的应用前景.采用爆炸焊接技术成功制备了TC1/1060/6061复合板,对2个界面的界面形貌和元素进行测试,分析夹层存在的优势;同时建立与试验条件一致的有限元模型,对界面状态和焊接过程进行分析,最后对复合板进行拉伸试验和剪切试验,验证界面结合质量. 结果表明,TC1/1060界面为直线型形貌,1060/6061界面为波状形貌,且每个波形都伴随着涡流区,TC1/1060界面处的元素扩散范围为4.38 μm,且没有检测到钛/铝金属间化合物的产生.数值模拟再现爆炸焊接过程中射流的形成,界面温度沿着界面形貌分布,界面压力在碰撞点处达到最大,且呈现出椭圆形分布,复合板具有较高的抗拉强度和剪切强度,满足结构使用需求.     

Al／Ti／Steel覆板爆炸焊接界面的显微组织特征

利用电子显微技术研究了Ａｌ／Ｔｌ／Ｓｔｅｅｌ覆板爆炸焊接中两个异种焊接界面的显微组织变化特征，透射电镜直接取样观察到在界面处有组织过渡区，并且过渡区之间及过渡区与母材之间存在明显的边界，Ａｌ／Ｔｉ界面过渡区为Ａｌ＋Ｔｉ混合组织；Ｔｉ／Ｓｔｅｅｌ界面由ＦｅＴｉ金属间化合物区和非晶区组成；过渡区的形态和宽度与焊接过程中的合金元素扩散及冷却速度有关。     

Structural Transformations Occurring upon Explosive Welding of Alloy Steel and High-Strength Titanium

Features of the structure of a layered material welded by explosion of high-strength titanium alloy and tool roller steel with an intermediate layer of the structural low-carbon steel have been studied. The structural transformations occurring in materials upon their dynamic interaction have been analyzed. Particular attention is paid to the structure of vortex zones formed at the interfaces of billets of various steels, as well as structural steel and titanium-based alloy. The structural analysis methods made it possible to fix stable and metastable joints appearing upon the explosive welding of various metals. To reveal features of structural transformations caused by prolonged heating, billets of titanium alloy and structural steel were also joined by diffusion welding. It has been shown that, in the course of the diffusion welding process, a continuous layer of stable brittle intermetallic compounds is formed along the entire interface of the welded materials. In the explosively welded materials, the intermetallic phases are distributed locally and, thus, they have a weaker embrittlement effect.