共查询到20条相似文献,搜索用时 46 毫秒
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采用三种不同的焊接工艺对双相不锈钢S31803进行焊接试验,通过对接头微观组织、力学性能、氧含量及耐腐蚀性能的观察与测试,确定最佳焊接工艺参数,并分析了焊接工艺方法对焊接接头组织、力学性能和耐腐蚀性能的影响。结果表明:与GTAW,SMAW相比,GTAW+SAW焊接工艺获得的接头的冲击吸收能量和耐腐蚀性能均可以满足双相不锈钢的制造标准要求,可以在压力容器制造中广泛使用。 相似文献
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针对铸钢件ASTM A487 6A粉碎盘在生产过程中产生的裂纹、缩松、缩孔等缺陷的问题,对粉碎盘铸钢件可焊性进行了分析,提出了修复方案和合理的工艺参数.通过采用合理的焊补工艺,实现了该类铸钢件的缺陷修复. 相似文献
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双丝脉冲MIG焊作为高效化的不锈钢焊接方法,是目前焊接行业研发的热点之一,但是如何选择和调节双丝MIG焊的电流波形参数依旧是一个难点. 为了优化不锈钢焊接的焊接方法,提高焊接效率,文中以双相不锈钢为焊接工件,通过电流波形参数对比试验,研究了双丝梯形波双脉冲焊,双丝矩形波双脉冲焊以及双丝单脉冲焊对焊接质量的影响. 结果表明,在相同热输入的条件下,双丝梯形波双脉冲焊焊接稳定性好于双丝矩形波双脉冲焊和双丝单脉冲焊,且前者的焊接成形质量更高,可看到更多的鱼鳞纹,同时使不锈钢接头的的拉伸强度和硬度以及韧性显著提高. 相似文献
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《Science & Technology of Welding & Joining》2013,18(4):363-377
AbstractPitting Corrosion behaviour of similar and dissimilar metal welds of three classes of stainless steels, namely, austenitic stainless steel (AISI 304), ferritic stainless steel (AISI 430) and duplex stainless steel (AISI 2205), has been studied. Three regions of the weldment, i.e. fusion zone, heat affected zone and unaffected parent metal, were subjected to corrosion studies. Electron beam and friction welds have been compared. Optical, scanning electron microscopy and electron probe analysis were carried out to determine the mechanism of corrosion behaviour. Dissimilar metal electron beam welds of austenitic–ferritic (A–F), ferritic–duplex (F–D) and austenitic–duplex stainless steel (A–D) welds contained coarse grains which are predominantly equiaxed on austenitic and duplex stainless steel side while they were columnar on the ferritic stainless steel side. Microstructural features in the central region of dissimilar stainless steel friction welds exhibit fine equiaxed grains due to dynamic recrystallisation as a result of thermomechanical working during welding and is confined to ferritic stainless steel side in the case of A–F, D–F welds and duplex stainless steel side in the case of D–A welds. Beside this region bent and elongated grains were observed on ferritic stainless steel side in the case of A–F, D–F welds and duplex stainless steel side in the case of D–A welds. Interdiffusion of elements was significant in electron beam welding and insignificant in friction welds. Pitting corrosion has been observed to be predominantly confined to heat affected zone (HAZ) close to fusion boundary of ferritic stainless steel interface of A–F electron beam and D–F electron beam and friction weldments. The pitting resistance of stainless steel electron beam weldments was found to be lower than that of parent metal as a result of segregation and partitioning of alloying elements. In general, friction weldments exhibited better pitting corrosion resistance due to lower incidence of carbides in the microstructure. 相似文献
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以某院设计的两个项目中的蒸发罐实际使用情况为切入点,从2507双相不锈钢设备的使用环境和制作工艺两方面分析了钾盐蒸发罐发生腐蚀开裂现象的原因,进而讨论了如何在设计、制造及使用过程中避免双相不锈钢设备发生腐蚀。结果表明:双相不锈钢蒸发罐的使用环境和制造工艺均对其耐蚀性有很大的影响,尤其是当有焊接瑕疵和组装残余应力造成的应力集中,或在强酸、高温、高Cl~-含量介质溶液的环境中运行时,设备极易发生应力腐蚀裂纹。 相似文献
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Taís Campos Scalise Mara Cristina Lopes de Oliveira Isaac Jamil Sayeg Renato Altobelli Antunes 《Journal of Materials Engineering and Performance》2014,23(6):2164-2173
Stainless steels employed for manufacturing automotive exhaust systems must withstand severe thermal cycles, corrosive environment due to urea decomposition, and welding operations. AISI 409 ferritic stainless steel can be considered a low-cost alternative for this application. However, depending on the manufacturing conditions during welding cycles, this material can be sensitized due to the precipitation of chromium carbides at grain boundaries. In this work, the intergranular corrosion resistances of the AISI 409 ferritic stainless steel were evaluated after annealing at 300, 500, and 700 °C for 2, 4, and 6 h. Solution-annealed samples were also tested for comparison purposes. Two methodologies were used to assess the sensitization behavior of the 409 stainless steel samples: the first one was based on the ASTM A763 (practice W), while the second one was based on the double-loop electrochemical potentiodynamic reactivation test. It was possible to identify that the annealing treatment performed at 500 °C was more critical to the occurrence of intergranular corrosion. 相似文献
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双相不锈钢焊接接头的耐蚀性研究 总被引:1,自引:0,他引:1
综述了双相不锈钢的焊接接头的耐蚀性研究进展及采用的研究方法和已取得的成果。主要介绍了双相不锈钢在焊接过程中,不同的热处理方式、不同的焊接工艺给双相不锈钢焊接接头的耐蚀性带来的影响。结果表明,采用合适的输入热能量、多层焊接、Ar+2%N2混合保护气、手工电弧焊(SMAW)和钨极氩弧焊(TIG)相配合,可以使得焊接接头具有优良的耐蚀性能。 相似文献
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主要介绍了2.25Cr-1Mo不锈复合钢板的焊接工艺试验和工艺评定,阐明了2.25Cr-1Mo锈复合钢板焊接工艺的可行性,实践证明,该工艺能满足使用要求。 相似文献
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Mehdi Rahmani Abbas Eghlimi Morteza Shamanian 《Journal of Materials Engineering and Performance》2014,23(10):3745-3753
To study the effect of chemical composition on microstructural features and mechanical properties of dissimilar joints between super duplex and austenitic stainless steels, welding was attempted by gas tungsten arc welding process with a super duplex (ER2594) and an austenitic (ER309LMo) stainless steel filler metal. While the austenitic weld metal had vermicular delta ferrite within austenitic matrix, super duplex stainless steel was mainly comprised of allotriomorphic grain boundary and Widmanstätten side plate austenite morphologies in the ferrite matrix. Also the heat-affected zone of austenitic base metal comprised of large austenite grains with little amounts of ferrite, whereas a coarse-grained ferritic region was observed in the heat-affected zone of super duplex base metal. Although both welded joints showed acceptable mechanical properties, the hardness and impact strength of the weld metal produced using super duplex filler metal were found to be better than that obtained by austenitic filler metal. 相似文献
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C. F. Salvador 《腐蚀工程科学与技术》2013,48(8):573-580
Flux-cored arc welding (FCAW) is an automatic welding process widely employed to join duplex stainless steel (DSS) structures in industrial plants because of its high productivity. However, when multiple passes are performed, this process can lead to the formation of non-metallic inclusions originating from the slag in the fusion zone. In this case, the welded joint can be repaired using the same welding process. Some regions next to the heat-affected zone are not removed during the repairing operation. Thus, these regions are subjected to repeated welding cycles and to a high heat input, which can cause microstructural alteration that impairs the corrosion resistance of the welded material. The aim of this work was to study the corrosion resistance of 2304 DSS plates joined using the FCAW process and repaired using the same process. The influence of the repair procedure on the corrosion resistance of the welded joints was evaluated using potentiodynamic polarisation and chronoamperometric curves, which allow the determination of the critical pitting temperature of the samples. The microstructure obtained after each repair cycle was evaluated using optical microscopy and scanning electron microscopy. The results showed that the corrosion resistance was depressed as the number of repair cycles increased. 相似文献
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《Science & Technology of Welding & Joining》2013,18(1):17-22
AbstractThe effect on laser welding of activating flux, originally developed to improve penetration depth for tungsten inert gas welding, was investigated. Both mild and stainless steels were tested. Results show that weld penetration capability relates closely to the laser power level and welding speed of the process. Significant improvement in penetration was only observed when laser welding was performed in the conduction mode (i.e. weld aspect ratio <1). For the range of parameters studied, the best penetration capability improvements achievable for mild steel, type 304 stainless steel, and duplex stainless steel were found to be 41, 53, and 63% respectively. These data are of use in the selection of parameters for laser welding with activating flux. 相似文献
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分析了双相不锈钢阀门铸件经常出现裂纹缺陷的原因.为避免再次投产时阀门铸件裂纹缺陷的产生,制定了相应的措施:提高砂芯的退让性;严格控制钢液的化学成分,特别是磷硫元素的含量控制;添加稀土元素细化晶粒,净化钢液以提高抗裂性;清除浇冒口和补焊注意温度的控制.结果表明,通过上述措施后,重新投产的阀门铸件没有裂纹缺陷. 相似文献
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