Microstructures and microhardness at fusion boundary of 316 stainless steel/Inconel 182 dissimilar welding

Journal Article · Tue Sep 15 04:00:00 EDT 2015 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2015.07.018· OSTI ID:22476171

Wang, Wei ^[1]; Lu, Yonghao ^[1]; Ding, Xianfei ^[1]; Shoji, Tetsuo ^[1]

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1. National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China)

Microstructures and microhardness at fusion boundary of a weld joint were investigated in a 316 stainless steel/Inconel 182 dissimilar weldment. The results showed that there were two alternately distributed typical fusion boundaries, a narrow random boundary (possessed 15% in length) with a clear sharp interface and an epitaxial fusion one with (100){sub BM}//(100){sub WM} at the joint interface. The composition transition, microstructure and hardness across the fusion boundary strongly depended on the type of the fusion boundary. For the random boundary, there was a clear sharp interface and the composition transition with a width of 100 μm took place symmetrically across the grain boundary. For the epitaxial fusion one, however, there were Type-I and Type-II grain boundaries perpendicular and parallel to the epitaxial fusion boundary, respectively. The composition transition took place in the Inconel 182 weld side. Σ3 boundaries in the HAZ of 316SS side and Σ5 grain boundaries in weld metal were usually observed, despite the type of fusion boundary, however the former was much more in epitaxial fusion boundary. Microhardness was continuously decreased across the random fusion boundary from the side of Inconel 182 to 316SS, but a hardening phenomenon appeared in the epitaxial fusion boundary zone because of its fine cellular microstructure. - Highlights: • Two typical fusion boundaries alternately distributed in the fusion interface • The microstructure, composition and hardness across fusion boundary depended on its type. • Different regions in welded joint have different special CSL value boundaries. • Hardening phenomenon only appeared in the epitaxial fusion boundary.

• OSTI ID: 22476171
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 107; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
EPITAXY
GRAIN BOUNDARIES
HARDENING
HEAT AFFECTED ZONE
INTERFACES
METALS
MICROHARDNESS
RANDOMNESS
STAINLESS STEEL-316
WELDED JOINTS