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In order to study the compositions and properties of NiTi alloy plasma arc welded joints, different temperatures of the heat-affected zone(HAZ) are simulated. Temperatures are set at 20 ℃, 400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃, 900 ℃ and 1 000 ℃. X-ray diffraction results of the thermal simulated specimens show that NiTi2 phase emerges in the alloy when the temperature is between 500 ℃ and 800 ℃, while NiTi2 and Ni3 Ti phases emerge when the temperature is between 800 ℃ and 1 000 ℃. Tensile strengths of specimens at 600 ℃ and 900 ℃ are only 68.0% and 61.3% of the strength at the roomtemperature respectively due to the emergence of NiTi2 and Ni3Ti phases. 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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研究了基于电焊条化学成分与熔敷金属抗拉强度的关系;讨论了网络隐含层神经元个数对预报结果的影响及其变化规律。 相似文献
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