Passive State Degradation of Stainless Steel Welds

2008 ◽  
Vol 138 ◽  
pp. 189-192
Author(s):  
Vladimír Číhal ◽  
Marie Blahetová ◽  
Zdenka Krhutová ◽  
Stanislav Lasek ◽  
E. Kalabisová
Keyword(s):  
Stainless Steel ◽  
Heat Affected Zone ◽  
Fusion Line ◽  
Passive State ◽  
Corrosion Attack ◽  
Preventative Measures ◽  
Steel Welds

Three types of corrosion attack frequently suffered by type Cr18Ni10 stainless steel in the heat-affected zone of welds were studied – knife-line, fusion-line, and fissure corrosion. Possible mechanisms and selected preventative measures were discussed in the light of microstructural findings.

Passive State Degradation of Stainless Steel Welds

2008 ◽  
pp. 189-192
Author(s):  
Vladimír Číhal ◽  
Marie Blahetová ◽  
Zdenka Krhutová ◽  
Stanislav Lasek ◽  
E. Kalabisová
Keyword(s):  
Stainless Steel ◽  
Passive State ◽  
Steel Welds

scholarly journals Exploratory Study of Sensitization in Cryogenically Cooled Ferritic Stainless Steel Welds

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
M. O. H. Amuda ◽  
S. Mridha
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Heat Affected Zone ◽  
Cryogenic Liquid ◽  
Cryogenic Cooling ◽  
Martensite Content ◽  
Steel Grades ◽  
Single Grain ◽  
Steel Welds ◽  
Aisi 430

Enhanced cooling via forced convection using cryogenic liquid is an option for controlling grain growth in the heat affected zone (HAZ) of ferritic stainless steel welds which improves joint strength. However, this technique seems to alter the martensite distribution in the high-temperature heat affected zone (HTHAZ) which is a critical constituent in rating the susceptibility to sensitization in ferritic stainless steel grades; any such information is not available in the literature. Thus, it is imperative to establish the influence of cryogenic cooling on sensitization dynamics in the HTHAZ. This paper discusses the influence of cryogenic cooling on sensitization in an AISI 430 ferritic stainless steel weld. It is established that cryogenic cooling increases the cooling rate in the HTHAZ and reduces the martensite volume percent by an average of 20%. This reduction in martensite content in the HTHAZ increases the level of ditched structure in cryogenically cooled welds and yields more ferrite-martensite ditched grain boundaries than in conventional welds. Although the cryotreated welds exhibit greater ditched boundary, the structure is still classified as nonsensitized, since no single grain boundary is completely surrounded by ditches.

Microstructure Analysis of Post Weld Aging in Duplex Stainless Steel Welds

2013 ◽  
Vol 717 ◽  
pp. 210-214
Author(s):  
Santirat Nansa-Arng ◽  
Prachya Peasura
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Phase Analysis ◽  
Stainless Steels ◽  
Heat Affected Zone ◽  
Parent Phase ◽  
Austenitic Stainless Steels ◽  
Ferrite Phase ◽  
Structural Applications ◽  
Steel Welds

Duplex stainless steel (DSS) offers an alternative to the austenitic stainless steels especially at temperatures between –50 and 300°C and is suitable for structural applications. The research was study the effect of post weld aging (PWA) parameters on microstructure in heat affected zone. The specimen was duplex stainless steel (DSS) UNS31803 which thickness of 10 mm. The PWA sample were tested the microstructure and phase analysis. The factors used in this study were PWA temperature of 650, 750, and 850๐C with PWA time of 1, 2, 4 and 8 hours. The welded specimens were tested by microstructure and phase analysis testing according to ASTM E3-11 code. The result showed that both of PWA temperature and PWA time can greatly affect microstructure and phase analysis in heat affected zone (HAZ). The ferrite that was austenite with a grain and an austenite scattered throughout. The microstructures of PWA 650 °C with PWA 1, 2, 4 and 8 hours in ferrite phase which ferrite phase was not different. The widmanstätten structures were observed high PWA temperatures were also distributed at grain. At high PWA temperature, ferrite at the grain boundary tended to decrease. Moreover excessive aging temperature can result in increasing austenite intensity and size in parent phase. Definitely, at high PWA temperature and time, over-aging of HAZ resulted in corrosion resistance reduce.

Microstructure characterization and corrosion testing of MAG pulsed duplex stainless steel welds

2017 ◽  
Vol 59 (7-8) ◽  
pp. 642-646 ◽  
Author(s):  
Ion Mitelea ◽  
Ion Dragoş Uţu ◽  
Sorin Dumitru Urlan ◽  
Olimpiu Karancsi
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Microstructure Characterization ◽  
Corrosion Testing ◽  
Steel Welds

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

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