热处理组织影响瑞利波评价碳钢表层应力的研究

Influence of microstructure on surface stress measurement of carbon steel by Rayleigh wave

基于瑞利波声弹性系数标定试验,采用一发一收瑞利波探头采集瑞利波信号,结合瑞利波信号分析探讨了热处理组织影响碳钢表层应力评价的机理。结果表明,随碳钢晶粒尺寸增大,瑞利波声弹性系数略有增大,瑞利波信号间时间差-载荷曲线的转折点载荷越接近试样弹性极限载荷,高载荷阶段瑞利波信号间时间差波动随载荷增大略有增大。分析认为,晶粒尺寸增大导致试样塑性变形能力下降、试样表面粗糙度及瑞利波探头与试样耦合质量是导致上述结果的重要原因。

Based on calibration test of Rayleigh wave acoustoelastic constant,two Rayleigh wave transducers with constant distance were used to collect Rayleigh wave signal,and the influence of carbon steel microstructure on surface stress measurement was discussed on the basis of signal analysis. Results show that as grain size of carbon steel increases,Rayleigh wave acoustoelastic constant of 45 steel increases slightly,turning point load between linear and nonlinear relationship on the curve of the difference in time of signal flight and load is close to elastic limit load,the fluctuation degree of the difference in time of signal flight in high stress stage slightly increases. The poor plastic deformation property due to the coarse grains of 45 steel is responsible for the above results,and it is also influenced by surface roughness of 45 steel and the coupling between ultrasonic transducer and surface of 45 steel.