钢制气瓶声发射特性分析-化工过程机械专业论文.docxVIP

摘要随着国民经济的飞速发展，集数式气瓶和长管拖车的数量越来越多。由于这 摘要 随着国民经济的飞速发展，集数式气瓶和长管拖车的数量越来越多。由于这 些气瓶盛装的介质常含有腐蚀性，易引发气瓶产生应力腐蚀等缺陷。而常规检测 手段很难有效识别早期缺陷，因此往往采用声发射检测技术，以弥补传统无损检 测的不足，提高缺陷检出率。但对于声发射检测技术，关键需要掌握不同材料产 生的声发射信号的特性，并有效识别出缺陷的种类。 本文以压力容器和气瓶的常用材料Q235B、16MnR、30CrMo为研究对象， 对它们的拉伸试样和30CrMo气瓶分别在塑性变形、缺口开裂、裂纹扩展时产生 的声发射信号进行了测定，并对测定结果进行了小波分析。结果表明，在相同实 验条件下，Q235B、16MnR、30CrMo三种材料的拉伸试样，在塑性变形、缺口 开裂、裂纹扩展时产生的声发射信号的小波分析能量分布有很大的区别，以此可 以区分出不同的材质。同一种材料在塑性变形、缺口开裂、裂纹扩展时产生的声 发射信号的小波分析wT最大值相差较大，可以根据这些特点检测出不同的缺 陷。 通过对30CrMo气瓶的实际声发射实验研究，并与30CrMo试样拉伸实验结 果进行了对比，结果表明，30CrMo气瓶和30CrMo试样的声发射特性小波分析 十分相似。所以在对30CrMo气瓶进行声发射特性分析时，可以考虑用30CrMo 拉伸试样来代替。 本文的研究结果为小波分析在声发射检测技术中的应用开拓了一个新的研 究方向，为今后材料和缺陷的声发射特性数据库的建立奠定了基础。 关键词： 声发射钢制气瓶小波分析无损检测 ABSTRACT111e ABSTRACT 111e number of the integrated gas cylinder and tube wailer is increasing all the time with the development of social economy．The gas cylinder is easy to be eroded or caused other disfigurement because of the erodible medium in it．In order to remedy the shortage of traditional NDT and improve the testing rate of disfigurement， acoustic emission(ALE)testing was used to instead of routine testing methods which could not find out the early disfigurement effectively．But，it was the key point for the AE technology that mastering AE characteristic of many different materials and recognizing the kinds of disfigurement． 乃e AE signals were tested for the tension samples ofQ235B、16Mng、30CrMo and the 30CrMo gas cylinder which Was at the state of plastic deformation，notch cracking and crack propagation point(PDNCCP)respectively．Then the wavelet analysis was conducted on the testing results．The results show that wavelet energy distribution ofAE signals propagated from Q23 5B、1 6MnR、30CrMo specimen at the state of PDNCCP is different from each other．So the different materials Can be distinguished with these characteristics．The same material has large discrepancy on the WT maximum of wavelet analysis，and the different disfigurement can be distinguished based on it． By comparing the AE ex