Journal Published Online: 22 May 2019
Volume 8, Issue 4

Residual Stresses, Microstructure, and Mechanical Properties of EB-Welded 90-mm-Thick UNS S41500 Martensitic Stainless Steel after PWHT

CODEN: MPCACD

Abstract

UNS S41500 is a grade of 13Cr-4Ni martensitic stainless steel utilized in hydroelectric turbine products. In this study, the microstructural characteristics, mechanical properties, and through-thickness residual stresses of electron-beam (EB) welded butt joints in 90-mm-thick UNS S41500, assembled using a single pass autogenous process, were evaluated after post-weld heat treatment (PWHT). The results of the longitudinal residual stresses, measured using the contour method, indicated that the applied PWHT was effective in stress relieving and reducing the hardness of the weldment through tempering of the “fresh” martensite present in the microstructure after EB welding. The static tensile properties that were evaluated in the directions transverse and longitudinal to the weld seam demonstrated high performance of the joints with conformance to the requirements of not only ASME Section IX, ASME Boiler & Pressure Vessel Code–Section IX: Qualification Standard for Welding and Brazing Procedures, Welders, Brazers, and Welding and Brazing Operators, but also ASTM A240, Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications, for unwelded UNS S41500. The Charpy impact energies indicated that the toughness of the welds greatly surpassed the minimum acceptance criteria specified in ASME Section VIII, ASME Boiler & Pressure Vessel Code–Section VIII: Rules for Construction of Pressure Vessels. Also, bend testing of transverse weld cross sections displayed no discontinuities on the tension side of the bent joints. These results provide the essential data for validating a manufacturing process for assembly of high-performance joints in an important hydroelectric turbine material.

Author Information

Sarafan, Sheida
École de Technologie Supérieure, Mechanical Engineering Department, Montreal, QC, Canada National Research Council Canada, Montreal, QC, Canada
Wanjara, Priti
National Research Council Canada, Montreal, QC, Canada
Lévesque, Jean-Benoît
Institut de recherche d’Hydro-Québec, Varennes, QC, Canada École de Technologie Supérieure, Mechanical Engineering Department, Montreal, QC, Canada
Gholipour, Javad
National Research Council Canada, Montreal, QC, Canada
Champliaud, Henri
École de Technologie Supérieure, Mechanical Engineering Department, Montreal, QC, Canada
Mathieu, Louis
General Electric Renewable Energy – Hydro North America, Bossard, QC, Canada
Pages: 16
Price: $25.00
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Stock #: MPC20180122
ISSN: 2379-1365
DOI: 10.1520/MPC20180122