During the past few years the industrial world has witnessed an anazing growth in the use of nondestructive testing methods and techniques. The demand for and use of nondestructive testing will continue to grow at an even more accelerated rate, For example, jet airplanes are operating at higher and higher speeds, jet and conventional airplane engines are developing greater horsepower per pound, and pressure vessels and pipes are operating at higher pres-

sures.18 As our technology advances further there will be a demand and need for new performance from engineering materials. To continue to make engineering advances and to meet the needs of the world's advancing technology, nondestructive testing methods and techniques must find wider applications and new methods and techniques must be developed. Our expanding technology is demanding not only more but better nondestructive testing.

前几年间，在利用无损探伤方法与工艺方面工业界取得了惊人的进展。对于无损探伤的要求会继续提高，它的应用范围也会加速扩大。譬如，喷气飞机飞得越来越快，喷气飞机和常规飞机发动机单位重量发出的功率（马力/磅）越来越强大，高压容器与管道承受的压力愈来愈高。随着工艺水平的进一步提高，对工程材料的性能提出了新的需求。为了继续推动工程进步，为了满足全世界技术进步的需要，无损探伤的方法与工艺必须得到更广泛的应用，同时还必须发展新方法、新工艺。我们的技术在不断扩展，这就不仅需要更多种无损探伤方法，而且需要更好的无损探伤方法。

The purpose of this book is to acquaint engineers, metallurgists, and other technical personnel both practicing and "to be" with the (1) basic principles of nondestructive testing, (2) kind of results which can be expected when using these tests, and (3) typical applications.1? 

The term "nondestructive testing" is used in this book as a general name given to all test methods which permit testing or inspection of material without impairing its future usefulness. From an industrial viewpoint, the purpose of nondestructive testing is to determine whether a material or part will satisfactorily perform its intended function.

本书的目的是使正在从事和即将从事无损探伤的工程师、冶金工作者及其他技术人员了解下面几方面的知识。第一，无损探伤的基本原理；第二，利用这类检测所获结果的类型；第三，典型的应用实例。

“无损探伤”这一术语在本书中是用来赋予可用来对材料进行检测或探伤面对材料今后的用途不会造成损害的各类测试方法的通用名称。从工业观点来看，无损探伤的目的，是确定一种材料或一个零件是否能满意地起到原本想起到的作用。