等离子喷涂法改善1Cr18Ni9Ti接头的疲劳性能

Fatigue properties improvement of stainless steel 1Cr18Ni9Ti welded joints by plasma spray process

焊接接头焊趾处的等离子喷涂层可改善焊缝截面形状变化，降低该处的应力集中，提高焊接结构的疲劳强度。采用1Crl8Ni9Ti不锈钢十字接头焊态和喷涂处理试样分别进行疲劳对比试验，并对试验结果进行统计分析。疲劳试验结果表明，等离子喷涂后1Crl8Ni9Ti接头疲劳性能明显改善。焊态试件的疲劳强度为169.8MPa，火焰喷涂试件为186.2MPa，等离子喷涂试件为213.8MPa，与焊态试件相比，等离子喷涂试件的疲劳强度提高25.9％，火焰喷涂试件提高9.7％。等离子喷涂试件的疲劳寿命是焊态试件的1.58～9.62倍，火焰喷涂试件的疲劳寿命是焊态的1.55～1.97倍。

Plasma sprayed coatings on the weld toe can modify the sectional dimensions of welded joints.It can also reduce the stress concentration of the toe.So the fatigue properties of the joints can be improved.The plasma spray process was used to improve fatigue properties of welded joints.The fatigue tests of the cruciform joints welded by TIG welding of stainless steel 1Cr18Ni9Ti under tensile load(R=0) were carried out on the as welded,flame sprayed and plasma sprayed specimens.Fatigue tests results showed that plasma spray process was effective to improve fatigue life of cruciform joints.The fatigue strength of the as welded specimens was 169.8MPa,and that of the flame sprayed and plasma sprayed specimens were 186.2MPa and 213.8MPa respectively.The fatigue strength of the plasma sprayed specimens had been increased by 25.9%,and that of the flame sprayed had been increased by 9.7%.The fatigue life of the plasma sprayed specimens was 1.58~9.62 times longer than that of the as welded ones,and that of the flame sprayed specimens was 1.55～1.97 times longer.