X80级感应加热弯管性能及静水压爆破试验分析

Analysis on Properties and Hydrostatic Burst Test of X80 Induction Heated Bending Pipe

采用力学性能试验分析了X80级φ1219 mm×22 mm感应加热弯管直管段、过渡区及弯曲段的强度及韧性变化规律,并结合其微观金相组织进行比对。结果显示,经过950~1000℃感应淬火、580~630℃回火后,X80感应加热弯管强度均超出标准要求,内弧侧管体强度最低而冲击韧性最高;中性区及右过渡区管体强度水平较高;外弧侧管体冲击韧性最低;同时,对感应加热弯管进行了静水压爆破试验,并测量了不同部位的应变值。随着水压不断增加,试验结果表明：弯管各点的横向微应变值大于纵向微应变值;弯曲段外弧侧附近的横向应变值高于弯管其他各点的应变值。当加压至24.5 MPa时,弯管在弯曲段外弧侧附近爆破失效。

The strength and toughness variation rule of straight part,transitional zone and bend part of X80 grade φ1219mm×22mm induction heated bending pipe were analyzed by the tests of mechanical properties,and the different part metallographic microstructures were investigated contrastively.The results showed that the strength of X80 induction heated bending pipe was beyond standard requirements after 950～1000℃ induction quenching and 580～630℃ tempering.The strength of inner arc side pipe body was lowest and impact toughness was highest;the strength of neutral zone and right transitional zone was higher;the impact toughness of outer arc side pipe body was lowest.At the same time,the hydrostatic burst test of induction heated bending pipe was carried out and the microstrain of different parts was measured.With hydraulic pressure increasing,the tests results indicated that the transverse microstrain of bending pipe was higher than that of longitudinal,nearby the outer arc in bend part,the transverse microstrain was higher than that of other points.When the pressure was up to 24.5MPa,the bending pipe bursted failure nearby the outer arc in bend part.