液化石油气储罐焊疤表面裂纹的磁记忆信号研究  

STUDY ON THE MAGNETIC MEMORY SIGNALS FROM THE WELDING SCAR SURFACE CRACKS OF LIQUEFIED PETROLEUM GAS TANK

作　　者：沈功田[1] 吴彦[1] 王勇[1] 

机构地区：[1]中国特种设备检测研究中心,北京100013

出　　处：《无损检测》2004年第7期349-351,共3页Nondestructive Testing

摘　　要：采用磁记忆检测发现液化石油气储罐焊疤部位存在较强的磁记忆信号。通过对储罐进行0～4.0MPa的加载试验,研究磁记忆信号的幅度和梯度随载荷的变化。最后采用磁粉探伤复验发现磁记忆信号部位存在大量3～5mm长的焊疤表面裂纹。试验结果表明,在0～2.0MPa的加压过程中,磁记忆信号的幅度和梯度均逐渐增大,到2.0MPa时达到峰值,在2.0～4.0MPa的加载过程中迅速下降,在此期间采用声发射监测,发现了七个声发射信号,证明该部位应力产生了迅速释放。由此证明磁记忆信号的幅度和梯度既与材料所处的整体应力有关,也与该部位的局部应力集中度有关。A typical signal was found in the position of welding scar of a liquefied petroleum gas(LPG) tank by metal magnetic memory testing (MMMT). The amplitude and gradient of MMMT signals were investigated through pressurizing the tank from 0 to 4MPa. 3～5mm long surface cracks were found by magnetic particle testing in the position of MMMT signals after pressurization. Results showed that the amplitude and gradient of MMMT signals increased from 0 to 2MPa and quickly decreased from 2 to 4MPa, and seven acoustic emission(AE) signals were monitored by AE instrument during the time. AE signals proved that stress release took place in the area. The amplitude and gradient of MMMT signals not only relied on the average stress of the shell, but also relied on the local stress concentration.

关 键 词：金属磁记忆检测 压力容器 裂纹 信号分析 

分 类 号：TG115.28[金属学及工艺—物理冶金]