Microstructure and mechanical property of the fusion boundary region in an Alloy 182-low alloy steel dissimilar weld joint

• Published in: Journal of materials science Vol. 45; no. 19; pp. 5332 - 5338
• Main Authors: Hou, J., Peng, Q. J., Takeda, Y., Kuniya, J., Shoji, T., Wang, J. Q., Han, E.-H., Ke, W.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2010; Springer; Springer Nature B.V
• Subjects: Alloy steels; Alloys; Austenitic stainless steels; Boron steel; Boundaries; Characterization and Evaluation of Materials; Chemical composition; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Degassing of metals; Dilution; Dissimilar material joining; Enrichment; Heat affected zone; High strength steels; Low alloy steels; Martensite; Materials Science; Mechanical properties; Metals; Microstructure; Nickel base alloys; Nickel molybdenum steels; Organic chemistry; Polymer Sciences; Solid Mechanics; Specialty metals industry; Specialty steels; Steel alloys; Welded joints; Stress Corrosion Crack; Lath Martensite; Martensite; Weld Metal; PWHT
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-010-4581-6

Characterizations of the microstructure and mechanical property of the fusion boundary region of an Alloy 182-A533B low alloy steel (LAS) dissimilar weld joint were conducted. The existence of type-II boundary that parallels to the fusion boundary in the dilution zone (DZ) of Alloy 182 within a distance of about 50 μm was observed. The chemical composition transition was found in the narrow zone between the type-II and the fusion boundaries. Highest hardness was also found in this narrow zone in the fusion boundary region, implying a high residual strain level in the narrow zone. Lath martensite was observed in both sides of the type-II boundary in DZ, suggesting the localized enrichment of Fe and C adjacent to the type-II boundary due to the diffusion from LAS to DZ. Massive precipitations of carbides were observed on the type-II boundary but not on the fusion boundary. In addition, the orientation relationship at the fusion boundary between the lath martensite in the heat-affected zone in LAS and the austenite in the DZ was found to be Bain, K–S and N–W relationships.