共查询到18条相似文献,搜索用时 641 毫秒
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对SAF2205/16MnR双相不锈钢复合板进行了焊接,基层采用手工电弧焊,以E5015焊条为填充材料,过渡层及覆层采用钨极氩弧焊,以ER2209焊丝为填充材料;对焊接接头进行了拉伸试验,利用扫描电镜、光学显微镜及X射线衍射仪等分析了接头过渡层焊缝及其熔合区域的显微组织及物相组成.结果表明:焊接接头的抗拉强度为512 MPa;覆层母材/热影响区/过渡层焊缝之间的显微组织过渡缓和,且铁素体和奥氏体相的比例均在控制范围内;异种金属熔合界面未出现明显的合金元素短程扩散,且在焊缝金属中未发现有M23C6和σ等脆性相析出;所得接头具有良好的力学性能和耐腐蚀性能. 相似文献
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选用连续施焊、焊层冷至室温后再焊接下一层、焊道冷至室温后再焊接下一道3种层间温度控制方案和730,600℃2种焊后退火温度,通过显微组织、拉伸性能和疲劳性能确定了大厚度TC4钛合金铸造板钨极惰性气体保护焊(GTAW)的最优工艺,并研究了最优工艺下焊接接头的力学性能。结果表明:焊层冷至室温后再焊接下一层得到的焊接接头焊缝组织最为细小,疲劳寿命最高,在730℃下退火后的焊接接头拉伸性能更好,故确定为最优工艺;最优工艺下,GTAW接头的焊缝硬度略高于母材,属于高匹配接头,在拉伸和疲劳过程中接头均在母材处发生断裂,但焊缝的抗疲劳开裂能力低于母材。 相似文献
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本文采用钢焊条手工电弧焊焊接铜钢接头进行实验,强度检测表明:接头抗拉强度达到铜本体强度,金相组织表明焊缝结合良好,界面无气孔、夹渣、未熔合等缺陷.实验证实手工电弧焊铜钢接头需650~700℃预热,采用碱性焊条焊缝性能优于酸性焊条,减小熔合比有助提高焊缝质量. 相似文献
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李刚 《机电产品开发与创新》2015,28(3)
针对ZG0Cr25Ni7Mo2N低碳双相不锈钢产品在生产中出现的焊接不稳定问题,经常出现返修补焊的现象,论文对ZG0Cr25Ni7Mo2N低碳双相不锈钢铸件补焊进行研究,使用焊条电弧焊的方法,选用2209-15低氢焊条,采用多层多道焊,通过确定合理的工艺参数及焊接方法,分析焊接接头的金相组织,对焊接接头力学性能进行检测,验证ZG0Cr25Ni7Mo2N低碳双相不锈钢在使用2209-15低氢焊条,采用所选焊接工艺条件下,焊接接头是否能满足产品要求。解决双相不锈钢铸件焊接产品在精加工出现缺陷。经过试验确定,焊接热影响区主要由双相组织组成,焊缝区域主要由奥氏体组织和少量铁素体组织组成,焊接接头力学性能满足使用要求. 相似文献
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FV520(B)钢异种钢焊接接头的组织和性能研究 总被引:1,自引:0,他引:1
通过拉伸试验、示波冲击试验和硬度试验,对两种焊后热处理(850℃油淬+560℃时效、850℃油淬+600℃时效)下的沉淀硬化不锈钢FV520(B)/低碳调质钢18CrMnMoV异种钢焊接接头的组织和力学性能进行了研究,结果表明:两种焊接接头中,焊缝组织粗大,硬度最高,韧性最低;600℃时效处理后的焊缝和两种母材的硬度均低于560℃时效处理后的焊接接头的相应位置的硬度,但前者的韧性高于后者;在两种焊接接头中的FV520(B)母材侧热影响区均存在软化区,这是导致两种焊接接头在拉伸试验中均断裂于该位置的主要原因;600℃时效的焊接接头具有比较合理的综合力学性能。 相似文献
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采用金相显微镜、里氏硬度计、马沸炉等研究焊接方式、热处理工艺对Q235B焊缝区微观组织和硬度的影响。结果表明,在相同的焊接电流下,采用CO2气体保护焊获得的焊缝组织均匀性优于采用焊条电弧焊、钨极惰性气体保护焊的焊缝;不同大小焊接电流CO2气体保护焊获得的焊缝组织,成分区别不大,采用160A焊接电流的焊缝组织晶粒比190A焊接电流的要粗大,采用220A焊接电流的焊缝组织均匀性最好;不同焊接速度CO2气体保护焊获得的焊缝组织,采用600 mm/min焊接速度的焊缝组织,成分分布最为均匀,组织致密性最好;采用230 mm/min焊接速度的焊缝组织晶体最粗大,采用375 mm/min焊接速度的次之,采用600 mm/min焊接速度的最为细小;退火处理工艺(温度650℃,保温1.5 h,随炉冷却到300℃,取出空冷到室温)总体上有利于焊缝组织的晶粒细化和均匀分布;退火处理前的焊缝硬度普遍高于母材的硬度,焊条电弧焊焊缝硬度平均值最大,退火处理后的焊缝硬度,除了第一组试样中CO2气体保护焊的焊缝之外,其余焊缝的硬... 相似文献
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Yan-Wen Huang Pi-Cheng Tung Cheng-Yu Wu 《The International Journal of Advanced Manufacturing Technology》2007,34(1-2):56-61
A new method to tune the gains of the proportional integral derivative (PID) controller for alternating current shield metal
arc welding (SMAW) of automatic arc welding system using a SMAW process is presented in this paper. This method used the genetic
algorithm (GA) approach to optimize the gains of the PID auto-tuner and considerably modulated the rate of an electrode feed
mechanism that regulates arc current. The proposed controller was verified by simulation and experiments of the transient
response in the automatic arc welding system. Finally, the performance indices of the proposed controller are compared with
that based on Ziegler–Nichols tuning rules. 相似文献
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高强钢厚板激光-GMAW复合双面同步横焊特性研究 总被引:3,自引:0,他引:3
针对30 mm厚船用高强钢10Ni5Cr Mo V对接接头横焊应用需求,开展激光-熔化极气体保护电弧(Gas metal arc welding,GMAW)复合双面同步横焊特性研究。研究结果表明,针对横焊位姿因重力、非对称坡口对熔滴、电弧的影响,利用激光对电弧的吸引和收缩作用,通过减小光-丝间距,有效地抑制了电弧侧壁燃弧,熔滴在电磁力和等离子流力的作用下,稳定过渡到熔池中,实现了熔滴过渡稳定性控制,解决了激光-GMAW复合横焊位姿电弧偏离和熔滴下落等过程控制难题与侧壁未熔合问题;厚板激光-GMAW复合双面同步横焊包括打底层和填充层焊接,其中打底层焊接是保证接头焊接质量的关键;采用激光-GMAW复合双面同步横焊新方法,4道焊接完成了30 mm厚船用高强钢10Ni5Cr Mo V横焊位姿的高强、高效连接。焊缝表面成形良好,无裂纹、未焊透和侧壁未熔合等缺陷。接头的抗拉强度高于母材,且其–50℃冲击吸收能量为57.3 J。 相似文献
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V. Balasubramanian V. Ravisankar G. Madhusudhan Reddy 《The International Journal of Advanced Manufacturing Technology》2008,36(3-4):254-262
High strength aluminum alloys (Al-Zn-Mg-Cu alloys) have gathered wide acceptance in the fabrication of lightweight structures
requiring high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway
transport systems. The preferred welding processes of high strength aluminum alloy are frequently the gas tungsten arc welding
(GTAW) process and the gas metal arc welding (GMAW) process due to their comparatively easy applicability and better economy.
Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal
solidification. This often results in inferior weld mechanical properties and poor resistance to hot cracking. In this investigation,
an attempt has been made to refine the fusion zone grains by applying a pulsed current welding technique. Rolled plates of
6 mm thickness were used as the base material for preparing single pass welded joints. A single ‘V’ butt joint configuration
was prepared for joining the plates. The filler metal used for joining the plates was AA 5356 (Al-5Mg (wt%)) grade aluminum
alloy. Four different welding techniques were used to fabricate the joints: (1) continuous current GTAW (CCGTAW), (2) pulsed
current GTAW (PCGTAW), (3) continuous current GMAW (CCGMAW) and (4) pulsed current GMAW (PCGMAW). Argon (99.99% pure) was
used as the shielding gas. Tensile properties of the welded joints were evaluated by conducting tensile tests using a 100 kN
electro-mechanical controlled universal testing machine. Current pulsing leads to relatively finer and more equi-axed grain
structure in GTA and GMA welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain
structures. Grain refinement is accompanied by an increase in tensile strength and tensile ductility. 相似文献
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Marco Paulo Lages Parente Renato M. Natal Jorge A. Aguiar Vieira A. Monteiro Baptista 《The International Journal of Advanced Manufacturing Technology》2012,60(1-4):127-134
In this study, commercially pure titanium sheets (American Society for Testing and Materials grade?2) were welded by resistance spot welding at various welding parameters. The welded joints were subjected to tensile-shearing tests in order to determine the strength values. In addition, the hardness and microstructural examinations were carried out in order to examine the influence of welding parameters on the welded joints. The experimental results showed that increasing electrode force, welding current and welding time increased the tensile-shearing strength of the welded specimens. Hardness measurement results indicated that welding nugget had the highest hardness and this was followed by the heat-affected zone and the base metal. Microstructural examinations showed the growth of the weld nugget grains with increasing heat input. Besides, due to plastic deformation during the welding process, twins were formed and at the same time twins increased with increasing electrode force, welding current and welding time. 相似文献
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A study on mechanical characteristics of the friction stir welded A6005-T5 extrusion 总被引:1,自引:0,他引:1
Weon-Kyong Kim Si-Tae Won Byeong-Choon Goo 《International Journal of Precision Engineering and Manufacturing》2010,11(6):931-936
In this paper, A6005-T5 extruded aluminum alloy sheets which are used for floor, roof or wall panels of railroad vehicles
were welded by the friction stir welding (FSW) and gas metal arc welding (GMAW) techniques. The mechanical characteristics
including the tensile strength, micro-hardness and fatigue strength of the FSW joint were compared to those of the base metal
and GMAW joints. In order to determine the relationship between the welding variables of FSW and the mechanical characteristics
of the joint, the response function was derived using the least square method and the sensitivity analysis was performed.
The rotational speed, welding speed and tilting angle of the welding tool were chosen as design variables. On the basis of
the Plackett-Burman design table, eight different FSW experiments were done, and then the effects of design variables on the
mechanical characteristics of the FSW joint were analyzed. The result showed that the welding speed has a most significant
effect on the tensile and fatigue strength. In the case of the micro-hardness, the effect of the tilting angle was the biggest. 相似文献