中文摘要：

无损检测是检测锅炉、压力容器的各种原材料及焊缝是否存在危险性缺陷或非允许缺陷的现代检验技术.以理论为依据,探讨了衰减分贝与衰减系数在超声波探伤中的应用.由分贝推导出超声波探伤的基本公式,找出返回声压与衰减分贝值之间的变化规律,介绍了超声波在工件内传播过程中衰减系数及其求解.在探伤实践操作中,使缺陷的定量有了可靠的理论依据.

英文摘要：

Nondestructive testing is a kind of modern testing technology,the technology for detecting boiler and pressure vessel of various raw materials and welding lines in which the hazardous defects exist or not.Based on the theory,discusses the attenuation decibel and attenuation coefficient in the application of ultrasonic inspection.The basic formula of ultrasonic inspection is derived by the decibel,finding out the variation between back pressure and attenuation decibel value,introducing the ultrasonic attenuation coefficient and its solution in the process of transmission at the inner part.In the testing practice,there is a reliable theoretical basis in terms of quantitative defects.