Effect of Plastic Deformation and Subsequent Heat Treatment on the Acoustic and Magnetic Properties of 12Kh18N10T Steel

Abstract

This paper presents results from studies on the effect of plastic deformation and subsequent heat treatment on the acoustic and electromagnetic properties of 12Kh18N10T austenitic steel. Widely used in industry, 12Kh18N10T cryogenic corrosion-resistant austenitic steel is interesting because upon plastic deformation the martensitic phase within it occurs, which significantly changes the electromagnetic, elastic, and strength properties of the material. The formation of a new phase together with the process of plastic deformation affects the crystallographic texture of the alloy, which impacts such parameter as acoustic anisotropy. Changes in the magnetic properties connected with appearance of the ferromagnetic phase of martensite in the paramagnetic austenite matrix were detected with an eddy current ferrite meter. It is found that, at the initial stage of plastic deformation (uniaxial tension), the value of the acoustic anisotropy parameter decreases. Probably, this is connected with the fact that the change in the texture is more affected by the deformation of austenite than the formation of α′-martensite. Further deformation of the material causes more intense formation of the new phase and its impact on the crystallographic texture becomes predominant, which results in the increase in the parameter of acoustic anisotropy. It is also found that annealing of 12Kh18N10T pre-deformed stainless steel at temperatures of 350, 600, 700, and 1050°C decreases the parameter of acoustic anisotropy and the volume content of the magnetic phase. At the temperature of 600°C, the acoustic anisotropy of the material drops to zero, whereas at the temperature of 1050°C, the martensitic phase is completely disintegrated and the texture is determined only by the austenitic phase.