X-Ray Stress Measurement of Two-Phase Stainless Steel

Abstract

The X-ray elastic constants of two-phase stainless steel and four kinds of 18-8 stainless steel tensile pre-strained at low temperatures were measured by the ψ₀ oscillation method with CrKβ γ(311) diffraction and CrKα α(211) diffraction, and the accuracy of the measurements was examined.
The results obtained are summarized as follows.
(1) When CrKβ γ(311) diffraction plane was used, the value of constant K_X was not much influenced by the amount of α-phase. The K-value (K_X=37.26kg/mm²/deg) of the austenitic stainless steel reported in the joint research by the Committee on the Mechanical Behaviour of Materials was considered suitable for X-ray stress measurement of two-phase stainless steel such as ferrite-austenitic stainless steel and strain-induced metastable austenitic stainless steel.
(2) On the CrKα α(211) diffraction plane, it seemed that the value of constant K_X for the two-phase stainless steel differed from the K-value for ferritic steel (K_X=-32.44kg/mm²/deg).
(3) In the X-ray stress measurement of the two-phase stainless steel with the CrKβ γ(311) diffraction intensity curve influenced by CrKα α(211) diffraction, the measured stress value increased up to 4kg/mm² by the influence of α(211) profile under the present experimental conditions.