Influence of Si on sigma phase precipitation and pitting corrosion in superaustenitic stainless steel weld metal

2018 ◽  
Vol 207 ◽  
pp. 91-97 ◽  
Author(s):  
Changmin Lee ◽  
Sungjoo Roh ◽  
Changhee Lee ◽  
Seunggab Hong
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Pitting Corrosion ◽  
Sigma Phase ◽  
Steel Weld ◽  
Phase Precipitation ◽  
Superaustenitic Stainless Steel ◽  
Stainless Steel Weld ◽  
Steel Weld Metal ◽  
Stainless Steel Weld Metal

scholarly journals Prediction of ^|^sigma; Phase Precipitation in Type 316FR Stainless Steel Weld Metal

2013 ◽  
Vol 31 (4) ◽  
pp. 168s-172s ◽  
Author(s):  
Eun Joon Chun ◽  
Hayato Baba ◽  
Koji Terashima ◽  
Kazutoshi Nishimoto ◽  
Kazuyoshi Saida
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Sigma Phase ◽  
Steel Weld ◽  
Phase Precipitation ◽  
Stainless Steel Weld ◽  
Steel Weld Metal ◽  
Stainless Steel Weld Metal

Effect of Residual Elements on Fracture Characteristics and Creep Ductility of Type 308 Stainless Steel Weld Metal

1975 ◽  
Vol 97 (3) ◽  
pp. 245-250 ◽  
Author(s):  
J. O. Stiegler ◽  
R. T. King ◽  
G. M. Goodwin
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Sigma Phase ◽  
Total Elongation ◽  
Steel Weld ◽  
Creep Ductility ◽  
Stainless Steel Weld ◽  
Steel Weld Metal ◽  
Residual Elements ◽  
Stainless Steel Weld Metal

Previous studies had shown that conventional type 308 stainless steel weld metal can have low creep ductility (< 1 percent total elongation) at 650 deg C. This paper demonstrates that the low ductility results from internal cracks that develop at austenite-sigma phase boundaries and propagate under the test conditions. The sigma phase is formed from ferrite present in the as-deposited weld metal. Type 308 stainless steel weld metal containing controlled amounts of the residual elements B, P, and Ti also contains sigma phase, but phase boundary cracking has not been observed even after 5000 hr. The controlled residual element weld metal is significantly more ductile (> 10 percent total elongation) than the conventional weld metals for which data are available.

Effects of Isothermal Aging on Tensile Properties and Fracture Behavior of 316L Austenitic Stainless Steel Weld Metal

2009 ◽  
Vol 83-86 ◽  
pp. 1182-1189
Author(s):  
A. Karimian ◽  
Hassan Farhangi ◽  
A. Amari Allahyari
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Fracture Behavior ◽  
Sigma Phase ◽  
Steel Weld ◽  
Stainless Steel Weld ◽  
Steel Weld Metal ◽  
316L Austenitic Stainless Steel ◽  
Stainless Steel Weld Metal ◽  
Austenitic Stainless Steel Weld

In this research, variations of tensile properties and fracture behavior of 316L austenitic stainless steel weld metal as a function of aging temperature and time have been investigated. Stainless steel plates were butt-welded using GTAW process. Weld metal tensile specimens were subjected to various aging heat treatments at temperatures of 750 and 850°C for periods of 1 to 100 hours prior to tensile tests at 25 and 500°C. Dissolution of delta-ferrite and formation of sigma phase network during aging resulted in a mild increase in tensile strength and significant reduction in ductility, particularly at 25°C. Although fracture surfaces exhibited ductile features, the dimple morphology and the macroscopic fracture mode were found to be affected by aging. The unaged weld metal exhibited a classic mode of cup and cone fracture, whereas slant and flat types of fracture modes were observed in the aged weld metals, with the slant mode being dominant at 500°C. The slant mode was associated with deformation localization along arrays of primary voids, nucleated at cracked sigma phase particles, oriented at about 45° to loading direction. The transition in the fracture mode is further discussed based on variations in the dimple morphologies and strain hardening exponent.

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