Influence of cross correlation step length on the surface stress of thin laser cladding Fe314 alloy coatings

Bin Liu1,2), Shi-yun Dong2), Bin-shi Xu2), and Peng He1) 1) State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China 2) National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072, China

摘 要：To measure the surface stress of thin laser cladding coatings with Rayleigh waves based on the cross correlation function, this pa-per introduced the influence of cross correlation step length on the stress measurement. Flat-shaped specimens made of laser cladding Fe314 alloy coatings were performed by static tensile tests, and Rayleigh wave signals were collected during the test process with an ultrasonic pulser and receiver instrument combined with two Rayleigh wave transducers. The difference in time of flight between two signals was de-termined based on the cross correlation function. The microstructure was observed by scanning electronic microscopy. The influence of the stress on the propagation velocity of Rayleigh waves and the relationship between the difference in time of flight and tensile stress under dif-ferent cross correlation step lengths were analyzed. The inhomogeneous deformation of the coatings affects the relationship between the dif-ference in time of flight and tensile stress; the stress measurement of the coatings is nearly constant with the increase of cross correlation step length when it attains one cycle.

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