共查询到20条相似文献,搜索用时 15 毫秒
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304不锈钢薄板脉冲激光焊焊接热过程数值分析 总被引:1,自引:1,他引:0
针对不锈钢薄板脉冲激光焊接的特点,基于有限元分析软件ANSYS,对0.5 mm厚的304不锈钢薄板脉冲激光焊接的热过程进行三维数值动态模拟.建模时采用实体单元和表面单元结合,并采用焊缝处细密、远离焊缝处粗略的不均匀网格,除了施加整体与外界的对流散热条件外,还考虑了工件与夹具之间的传导换热,分析了焊接温度场在工件上的分布规律及工艺参数对焊缝成形的影响,并据此提出了提高不锈钢薄板激光焊焊接接头质量的方案.计算结果表明,熔池的尺寸随输入能量的变化较为明显,在激光加热0.05 s后材料开始熔化,熔池呈现大幅度增长趋势;焊接速度对熔深和熔宽的影响较为显著,熔宽随焊接速度的增加而逐渐减小,熔深几乎与焊接速度成反比,当焊接速度约为0.4 m/min时,熔深为0.5mm以上,工件熔透,且深宽比可达到2∶1.计算所得熔池大小与试验结果基本吻合. 相似文献
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通过超声波检验、化学成分分析、金相检验、硬度测试等方法对304不锈钢钢管焊接断裂原因进行了分析。结果表明:由于冷却较为缓慢,造成热影响区附近铬贫化,使焊缝热影响区碳化物沿晶界析出,造成的晶间腐蚀是304不锈钢钢管焊接断裂的主要原因。 相似文献
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S. G. Lambrakos 《Journal of Materials Engineering and Performance》2013,22(8):2141-2147
An inverse thermal analysis of 304L stainless steel laser welds is presented. This analysis employs a methodology that is in terms of analytical basis functions. The results of this analysis provide parametric representations of weld temperature histories that can be adopted as input data to various types of computational procedures, such as those for prediction of solid-state phase transformations. In addition, these temperature histories can be used to construct parametric-function representations for inverse thermal analysis of welds corresponding to other process parameters or welding processes whose process conditions are within similar regimes. Specific aspects of the inverse-analysis methodology employed that relevant to its understanding and further development are examined. 相似文献
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Four surface treatments were given to AISI 304 SS in the cold-worked and heat-treated condition. The surface treatments were: exposure to laboratory air, exposure to 20% HNO3, anodization in H2SO4 with and without dissolved oxygen. Passive films thus obtained were characterised ellipsometrically and the refractive index and thickness values were measured.It was seen that the refractive index of films obtained in all cases except one was around 2.52, while in the case of the film obtained after anodization in H2SO4 with dissolved oxygen, it was seen to be 2.46. The thickness of films varied front 46 to 129 Å depending on the surface treatment. Heat-treatment appeared to have little effect on the type of film formed. 相似文献
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Prediction of Grain Growth Behavior in HAZ During Gas Tungsten Arc Welding of 304 Stainless Steel 总被引:1,自引:0,他引:1
H. Jamshidi Aval S. Serajzadeh A. H. Kokabi 《Journal of Materials Engineering and Performance》2009,18(9):1193-1200
In this study, the thermal cycles and the grain structure in the weld heat-affected zone (HAZ) are predicted. At the first
stage, a combined heat transfer and fluid flow model is employed to assess the temperature fields during and after welding
of 304 stainless steel and then, the evolution of grain structure is conducted using the predicted temperature distribution
and an analytical model of grain growth. The grain sizes of the CGHAZ (coarse grain heat affected zone) achieved from the
model are basically in agreement with those obtained from experimental measurement under different heat inputs in the range
of 0.33-1.07 MJ/m. Both the experimental data and the calculated results show that the average grain size near the fusion
plane is about two to four times larger than the average grain size in the base plate depending on the applied heat input. 相似文献
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对厚度仅为0.1mm的超薄304不锈钢板进行点焊时,其焊点焊接所需焊接能量要求控制精确,否则很容易造成烧穿或焊不上,很难达到预期的焊接质量要求。鉴此,提出了基于超级电容的储能焊焊机的研制。通过分析超级电容器原理及其模型,得出了将其应用于储能点焊的理论依据。根据储能电容组的电压与储能能量之间是平方关系,储能电容组的容值与储能能量之间为比例关系,在焊接板材超薄的情况下,提出了调节电容组容量的大小来调节焊接能量的方法。根据电阻点焊过程中动态电阻的变化规律对放电回路的电流进行控制,这样可较好地解决焊接规范较硬的问题。 相似文献
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对1Cr18Ni9Ti不锈钢焊接接头进行局部激光熔凝,观察激光熔凝后焊接接头组织的变化,并进行腐蚀试验。试验结果表明:在硫酸溶液中具有良好抗腐蚀性的不锈钢经焊接后.接头部位的抗腐蚀性较母材有所降低,但经激光熔凝后,抗腐蚀性可得到明显提高,这说明激光熔凝对改善不锈钢焊接接头的抗腐蚀性是有效的。 相似文献
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对1Cr18Ni9Ti不锈钢焊接接头进行局部激光熔凝,观察激光熔凝后焊接接头组织的变化,并进行腐蚀试验。试验结果表明:在硫酸溶液中具有良好抗腐蚀性的不锈钢经焊接后,接头部位的抗腐蚀性较母材有所降低,但经激光熔凝后,抗腐蚀性可得到明显提高,这说明激光熔凝对改善不锈钢焊接接头的抗腐蚀性是有效的。 相似文献
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以Φ45 mm×8 mm规格奥氏体304不锈钢钢管为研究对象,采用A-TIG焊(添加活性剂的钨极氩弧焊)进行对接焊接工艺试验,研究不同焊接起始点对焊缝成型的影响,并检测外观质量符合要求的焊件的性能和微观组织等。分析认为:采用A-TIG焊接工艺焊接Φ45 mm×8 mm规格奥氏体304不锈钢钢管时,可在不开坡口、不填丝的情况下,实现一次性焊透,并达到单面焊双面成型的目的;焊缝组织为奥氏体+铁素体,其组织与未添加活性剂时的一致,但添加活性剂可明显改善组织性能;焊接接头的性能满足标准要求。 相似文献
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