蠕墨铸铁超声检测影响因素的试验研究

Experimental Study on Influencing Factors of Ultrasonic Testing for Vermicular Graphite Cast Iron

借助Echometer1076超声波声速仪和定量金相分析,结合试验和数值模拟方法,对影响超声波法检测蠕化率的各因素如试样上下两表面的平行度、超声波探头与待测试样表面的垂直度、基体组织等进行了详细研究和系统分析。结果表明,试样上下两表面的平行度每改变0.1°,声速增加约4.58 m/s,对应的检测误差为0.086%。探头垂直度每改变0.1°,超声波声速减小约4.92 m/s,对应的检测误差为0.092%。声速随珠光体含量增加稍有增加。这些为精确测量声速和蠕化率提供了依据。

By means of the Echometer1076 ultrasonic sound velocity meter and quantitative metallography, combined with the experimental and numerical simulation, the factors such as the parallelism of the upper and lower surfaces of the sample, the incidence angle of the probe, and the matrix microstructure of the sample on the vermicular rate test of vermicular graphite cast iron were studied in details and systematically analyzed. The results indicate that the sound speed increases by about 4.58 rn/s and the corresponding detection error is 0.086% when the parallelism of the upper and lower surfaces of the sample changes by 0.1 degree. When the verticality of the probe changes by 0.1 degree, the ultrasonic speed decreases by about 4.92 m/s, and the corresponding detection error is 0.092%. The sound velocity increases slightly with the increase of pearlite content in the sample. These results provide a basis for the accurate measurement of sound speed and vermicular rate.