ULTRASONIC METHOD AND DEVICE FOR DETERMINING RESIDUAL STRESSES IN RAILS Russian patent published in 2024 - IPC G01N29/04 

FIELD: measurement.

SUBSTANCE: use for determination of residual stresses in rails. Substance of the invention consists in the fact that a small sample set of samples is formed from the rails melt, with selection of a sample set of a full-profile sample from each rail and cutting a groove in it in a cold state along the neutral axis of the sample. Wherein difference in sample heights ΔH_j is measured before and after cutting, and after said operations, residual stresses are measured in said cutting zone. To this end, an electromagnetic-acoustic transducer of the device for non-destructive testing is installed on the sample, at that, using the electromagnetic-acoustic converter, two transverse waves with orthogonal polarization along and across the longitudinal axis of the sample are excited normally to the input surface, which are reflected from the sample base and are received by the same electromagnetic-acoustic transducer. Further, the average value of acoustic anisotropy A in the measurement zone of residual stresses and the value of residual stresses σ_j in the sample are calculated. After receiving m-pairs of measured values of residual stresses σ_j and corresponding values ΔH_j, performing paired regression analysis of data, considering ΔH_j as an independent value, and σ_j as a response function, obtaining a statistically determined function σ=f(ΔH) of the dependence of the value of residual stresses in the rail on the difference in the measured values of the height of the sample before and after cutting the groove.

EFFECT: improving reliability and accuracy of determination of residual stresses in rails and provision of possibility to estimate residual stresses in various elements of a rail, including its head, web and base.

10 cl, 4 dwg, 1 tbl