| 2005 №05 (02) | 2005 №05 (04) |
The Paton Welding Journal, 2005, #5, 10-18 pages
Metal structure in the fusion zone and HAZ of welded joints on high-chromium heat-resistant steels
V.Yu. Skulsky
E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.Abstract
It is shown that a coarse-crystalline structure may form in the region between the weld and HAZ in fusion welding of high-chromium martensitic steels of P91 type. This structure is a fusion zone, wherein the base metal grains undergo a different degree of melting,. Segregation and diffusion redistribution of carbon may lead to formation of a relatively decarburized ferritic phase (δ-ferrite) within the fusion zone. Moreover, this zone is characterized by formation of coarse grains of primary austenite. It is shown that metal in the HAZ in the tempering region located behind the phase recrystallization region loses its strength.
Keywords: arc welding, high-chromium steels, welded joints, microstructure, weld, fusion zone, carbon, segregation, δ-ferrite, grain size, HAZ, tempering zone
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