Technology development for in-situ measurement of residual stress in arc welded joints of MDN 250 by portable Cosα X-ray diffraction method

Abstract

Residual stresses are inherent stresses that exist in engineering components even though no external load is applied. They are caused by the non-uniform volumetric shift of the metallic component during manufacturing processes. Welding is a key manufacturing technique that has a substantial impact on the economy since it is required for the production of a diverse variety of products used in the engineering sector. The residual stress primarily affects the stability, durability and performance of the welded joints. Hence its determination is of utmost importance. X-ray diffraction (XRD) is the most commonly used method for residual stress analysis. There are mainly two approaches for measuring residual stress using XRD; one is the sin2ψ method and the other is the cosα method. The residual stress measurements using the cosα method are handy, quick and convenient compared to the sin2ψ method. This method is well suited for welded joints, as it provides flexibility for testing immediately after the welding operation. Apart from residual stress measurements, the cosα method also gives valuable insights in the form of Debye-Scherrer (DS) rings and full width at half maximum. The present study focuses on the development of a novel technique that not only enables residual stress measurement but also provides a quantitative estimation of hardness and qualitative estimation of grain size without performing metallurgical or mechanical characterization. The material used for the present study is an arc-welded joint of MDN 250 grade maraging steel. The residual stress results show a compressive profile throughout the weldment, with a maximum value of compressive residual stress of 428 MPa at the fusion zone.

Evolution of microstructure, microhardness, crystallographic texture, and grain size variation in dissimilar joints used in concentrated solar power plants application

“…Because of the formation of fine grains, the transverse section of the FZ has a high hardness value. 31…”

“…Because of the formation of fine grains, the transverse section of the FZ has a high hardness value. 31 thermal conductivity, so a high amount of heat will be conducted from the SS side. Compared to the WC and IN625 sides, the SSWI had a higher HI, which caused the growth of grains in heat flow directions and resulted in columnar grains.…”

Characterization of weld joints produced by continuous wave and double pulse gas metal arc welding in naval grade high-strength low-alloy steel

“…Previous research has investigated the working concept (cos-α) and the relevance of the analysis to weldments. [24][25][26][27] The microhardness of the weldment was determined using a Vickers hardness tester (MMT-X) M/S (MATSUZAWA). Microhardness survey of the weldment cross-section includes BM on the right side, heat-affected zone (HAZ), and weld toward the right.…”

Analyzing microstructural, residual stress, and mechanical characteristics in dissimilar welds of Inconel 59 and AISI 904L through double-pulsed gas metal arc welding

“…The XRD-cosα method is a widely used technique for estimating the welding residual stress distribution in structures, offering distinct advantages over the sin 2 ψ method. 41 Although other methods, such as strain gauging or neutron diffraction, also provide valuable information about residual stresses, XRD stands out due to its nondestructive nature, high sensitivity, ability for quantitative measurements, consideration of crystallography, and capacity to cover a large volume. In addition, XRD provides depth-profiling capabilities, allowing the determination of residual stress at different depths within the material.…”