新型马氏体耐热钢P92是国内新引进的锅炉用钢，其具有较强的裂纹倾向，因此对P92钢焊缝的检测尤为重要。通过对钢焊缝常用的无损检测方法进行对比，认为超声波与磁粉检测相结合较为理想，但超声波在P92钢中的声速与普通碳钢中不同，造成实际探伤中会产生误差。为确保检验准确性，专门定制了P92材质对比试块，将普通碳钢试块上调好的距离-波幅曲线在P92对比试块上校准，从而解决了声速不同对缺陷定位、定量的影响。实践验证了超声波与磁粉相结合的检测方法对P92钢的有效性。

The P92 martensite steel is a new type of steel exclusive for boilers and characteristic of high heat resistance capability. The steel is however liable to crack. It is crucial to find applicable nondestructive methods to evaluate the steel weld. Through a thorough comparison between various available NDT means, the author found that the combination of ultrasonic and magnetic particle testing was a good choice. Considering that the sound wave velocity in P92 steel is different from ordinary carbon steel and the difference shall generate errors in result evaluation, specially made reference blocks of P92 steel are used to test the material, and calibrations are made by using the ordinary carbon steel with pre-adjusted distance-wave amplitude curves. Experimental results proved the effectiveness of ultrasonic testing combined with magnetic powder detection for the P92 steel.