摘要
为了探索超声红外热像检测技术对涂层下基体疲劳裂纹识别和评估的可行性,在Q235不锈钢试样中预置了拉伸疲劳裂纹,并采用火焰喷涂方法在试样表面制备了3Cr13合金涂层,使用25 k Hz低频脉冲超声波从涂层表面进行激励,研究了激励过程中涂层表面温度场的瞬态响应过程,以及裂纹区和非裂纹区的温度变化趋势;分析了表面喷涂层对基体裂纹开口处的生热机制的影响,提出了裂纹识别的最佳时间;通过二值化处理,基于MATLAB软件的数字图像处理功能,从热图中提取了裂纹骨架,并计算了裂纹长度。结果表明:超声红外热像法可实现对再制造毛坯涂层下基体疲劳裂纹的定性识别和定量检测。
To explore the practicability of fatigue cracks testing and evaluation in the substrate by ultra-sonic infrared thermal image technology,tensile fatigue cracks are prefabricated in Q235 stainless steel substrate,and 3Cr13 alloy coating is prepared on the surface of the sample by means of flame spray low-frequency ultrasonic with frequency of 25 kHz is employed to excite the specimen from coating surface. Transient response of coating surface temperature field in exciting process is researched,temperature vari-ation trend in crack area and non-crack area are compared;effect of themogenesis theory in crack branch-ing area caused by coating is analyzed,and the optimum time for crack recognition is put forward.Skele-ton path of the under-coating crack is extracted from binary thermal images with digital image processing of MATLAB software,and the crack length is calculated.The results show that ultrasonic infrared ther-mography can realize qualitative identification and quantitative detection of fatigue cracks of the subtrate under remanufacturing blank coatings.
出处
《装甲兵工程学院学报》
2016年第2期89-93,共5页
Journal of Academy of Armored Force Engineering
基金
国家"973"计划项目(2011CB13401)
关键词
再制造毛坯
疲劳裂纹
红外热像检测
图像处理
remanufacturing blank coatings
fatigue cracks
infrared thermal image detection
image processing
