超声冲击处理管接头疲劳设计曲线

Fatigue design curve of tubular joints treated by ultrasonic peening

关键词:  超声冲击处理  管接头  疲劳设计  S-N曲线

Key words:  ultrasonic peening treatment  tubular joint  fatigue design  S-N curve

摘要:

采用T形管接头形式进行了20钢及奥氏体不锈钢1Cr18Ni9Ti焊态与超声冲击处理态的疲劳对比试验,对超声冲击处理管接头疲劳设计问题进行了研究。结果表明:(1)用热点应力表征,对于承载前进行超声冲击处理的管接头,其疲劳设计曲线的斜率m采用10较为合适,而对于承载后进行处理的管接头,m采用3.0较为合适;(2)当应力比R=0,20钢及奥氏体不锈钢1Cr18Ni9Ti承载前超声冲击处理管接头的相应疲劳设计S-N曲线(热点应力表征)为lgN=30.78-10 lgS;(3)当R=0.5,20钢承载前和承载超声冲击处理管接头的疲劳设计S-N曲线(热点应力表征)分别为lgN=28.0-10 lgS和lgN=13.37-3 lgS。

Abstract:

T tubular joints were used in the fatigue contrast tests of low carbon steel and austenite stainless steel 1Cr18Ni9Ti in two conditions:welded and treated by ultrasonic peening.The aim is for fatigue design problem research of tubular joints treated by ultrasonic peening.Test results indicate that:(1) If attributed by hot spot stress,10 is more appropriate for the rate of slope m of the corresponding fatigue design S-N curve as for the tubular joints treated by ultrasonic peening before loading,while 3 is more appropriate for it as for the tubular joints treated by ultrasonic peening after loading.(2) Under the stress ratio R=0,the corresponding fatigue design S-N curve(attributed by hot spot stress,m=10) of low carbon steel and austenite stainless steel 1Cr18Ni9Ti tubular joints treated by ultrasonic peening before loading is lgN=30.78-10lgS.(3) Under the stress ratio R=0.5,the corresponding fatigue design S-N curve(attributed by hot spot stress,m=10) of low carbon steel tubular joints treated by ultrasonic peening before and under loading are lgN=28.0-10lgS and lgN=13.37-3lgS respectively.