Quantitative Estimation of Residual Stresses in Quenched Steel through Ultrasonic Parameters

Generally, residual stresses are present in the metal specimens after manufacturing and heat treatment processes. Quenching is a heat treatment process that forms residual stress in metals. Two testing methods are used to find residual stresses in the industry, which are Destructive and Non-Destructive. This research is focused on estimating residual stresses in quenched AISI 1045 Medium carbon steel using the Ultrasonic testing method as a non-destructive method. Water, Saltwater, and oil were used as three different quenching media to perform the quenching process. Ultrasound attenuation was used to measure the residual stresses in quenched steel, considering the difference in the attenuation coefficient before and after quenching. 12 mm thick AISI 1045 type steel sample was used to give the tensile stress, and the ultrasonic attenuation coefficient difference in stressed and zero-stressed conditions was measured. The obtained data were used to correlate the variation of stresses with the attenuation coefficient difference. Using this correlation and attenuation coefficient difference before and after quenching, we can estimate the residual stress of quenched steel samples. ABAQUS modeling software was used to simulate residual stresses. The Von Mises stress criterion was considered to be the simulation residual stress result. Those experimental and simulation values were compared for an identical correlation for residual stresses. The specimen's Centre Plane Von Mises stress criteria were considered to obtain the simulation stress values for comparison as maximum residual stresses occur in the Centre plane of the specimen. According to the experimental and simulation residual stress values, there is a Similarity between those values. Therefore, this methodology can be used to measure the internal residual stresses in quenched steel samples.