skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Solidification of an alloy 625 weld overlay

Abstract

The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy 625 weld overlay deposited on 2.25Cr-1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy, electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification at {approx}1,216 C by a {gamma}/Laves eutectic-type reaction. The Laves phase was highly enriched in Nb, Mo, and Si. The solidification reaction and microsegregation potential of major alloying elements in the overlay deposit are compared to other Nb-bearing Ni base alloys and found to be very similar to those for Alloy 718. Solidification cracks observed in the overlay were attributed to the wide solidification temperature range ({approx}170 C) and formation of interdendritic ({gamma} + Laves) constituent. Reasonable agreement is obtained between the calculated and measured volume percent ({gamma} + Laves) constituent with the Scheil equation by treating the overlay system as a simple {gamma}-Nb binary and using an experimentally determined k{sub Nb} value from electron microprobe data.

Authors:
 [1]
  1. Lehigh Univ., Bethlehem, PA (United States). Energy Research Center
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
413291
Resource Type:
Journal Article
Journal Name:
Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science
Additional Journal Information:
Journal Volume: 27; Journal Issue: 11; Other Information: PBD: Nov 1996
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 20 FOSSIL-FUELED POWER PLANTS; INCONEL 625; GAS METAL-ARC WELDING; SOLIDIFICATION; TURBINES; MATERIALS; CHEMICAL COMPOSITION; SUBSTRATES; STEEL-CR2MO; OPTICAL MICROSCOPY; ELECTRON MICROPROBE ANALYSIS; DIFFERENTIAL THERMAL ANALYSIS; TEMPERATURE DEPENDENCE; PHASE STUDIES; SEGREGATION; CRACKS; DENDRITES

Citation Formats

DuPont, J.N. Solidification of an alloy 625 weld overlay. United States: N. p., 1996. Web. doi:10.1007/BF02595452.
DuPont, J.N. Solidification of an alloy 625 weld overlay. United States. doi:10.1007/BF02595452.
DuPont, J.N. Fri . "Solidification of an alloy 625 weld overlay". United States. doi:10.1007/BF02595452.
@article{osti_413291,
title = {Solidification of an alloy 625 weld overlay},
author = {DuPont, J.N.},
abstractNote = {The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy 625 weld overlay deposited on 2.25Cr-1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy, electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification at {approx}1,216 C by a {gamma}/Laves eutectic-type reaction. The Laves phase was highly enriched in Nb, Mo, and Si. The solidification reaction and microsegregation potential of major alloying elements in the overlay deposit are compared to other Nb-bearing Ni base alloys and found to be very similar to those for Alloy 718. Solidification cracks observed in the overlay were attributed to the wide solidification temperature range ({approx}170 C) and formation of interdendritic ({gamma} + Laves) constituent. Reasonable agreement is obtained between the calculated and measured volume percent ({gamma} + Laves) constituent with the Scheil equation by treating the overlay system as a simple {gamma}-Nb binary and using an experimentally determined k{sub Nb} value from electron microprobe data.},
doi = {10.1007/BF02595452},
journal = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science},
number = 11,
volume = 27,
place = {United States},
year = {1996},
month = {11}
}