Q390高强抗震钢板残余应力检测方法对比及分析

利用盲孔法、X-Ray法、中子衍射法和超声法对Q390高强抗震板及U形弯曲件进行残余应力检测,并对这4种方法测试得到的应力结果进行分析研究。结果表明,以上4种检测方法均要考虑其特定的检测应用范围,X-Ray法针对钢板表面下微米级深度的微米级晶格尺度范围局部点应力进行检测,中子衍射法可在毫米级尺度局部区域进行应力检测,盲孔法反映的是因毫米尺度钻孔导致的钢板表面孔周边的应力变化,超声法则可以通过连续扫描检测整个钢板残余应力的宏观分布变化。因此,对于工业钢板,超声法测试残余应力更加科学、合理、准确。同时,通过U形试样建立稳定的应力应变场,利用超声设备使用不同参考态对Q390高强抗震板弯曲件及退火弯曲件进行测试,结果表明,测试参考态的选取对应力测试结果影响很大,材料各向异性的影响对应力测试结果不可忽视。

Comparison and analysis of residual stress detection methods for Q390 high strength seismic steel

Blind hole method, X-Ray method, neutron diffraction method and ultrasonic method were used to test the residual stress of Q390 high strength seismic plate and U-shaped bending parts, and the stress results obtained by several methods were analyzed and studied. The results show that the four detection methods need to consider their specific detection application range. The X-Ray method can detect local point stress in the micron-level lattice scale range of micron-level depth under the steel plate surface, and the neutron diffraction method can detect the millimeter-level scale and stress detection is carried out in local areas. The blind hole method reflects the stress change around the surface of the steel plate caused by millimeter-scale drilling. The ultrasonic method can detect the macroscopic distribution change of the residual stress for entire steel plate through continuous scanning. Therefore, for the application testing of industrial steel plates, ultrasonic testing of residual stress is relatively scientific, reasonable and accurate. U-shaped specimen was used to establish stable stress-strain field, and ultrasonic equipment was used to test Q390 high strength seismic bending parts and annealed bending parts with different benchmarks. The results show that the selection of test benchmarks has a great influence on the stress test results. The effect of anisotropy on the stress test results cannot be ignored.