scholarly journals The Microstructure and Pitting Resistance of 2002 Lean Duplex Stainless Steel after the Simulated Welding Thermal Cycle Process

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 70 ◽  
Author(s):  
Yuanyuan Yang ◽  
Yanjun Guo ◽  
Yuanyuan Liu ◽  
Jin Li ◽  
Yiming Jiang
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Strong Dependence ◽  
Austenite Phase ◽  
Cooling Rates ◽  
Pitting Potential ◽  
Lean Duplex Stainless Steel ◽  
Welding Thermal Cycle ◽  
Critical Pitting Temperature

In this paper, thermal cycles with different heat inputs and cooling rates were investigated for a novel lean duplex stainless steel 2002 using a welding simulation. The microstructure and pitting resistance of the simulated heat-affected zones were studied. With the increasing heat input, the amount and size of the austenite phase both increased, along with a transformation from rods to dendritic structures. The critical pitting temperature (CPT) and the pitting potential (Epit) both increased first and then declined as the heat input increased, indicating a strong dependence of pitting resistance on the heat input. For the different cooling rates, the amount of ferrite increased as the cooling rate increased from 0.25 °C/s to 20 °C/s. The CPT and Epit both increased with the increasing cooling rates, indicating an improved pitting resistance. The pits initiated preferentially at the boundaries of ferrite and austenite due to the precipitation of M23C6 in the specimens with different cooling rates.

Influence of Argon-Nitrogen Gas to Balance the Microstructure in the Welding of Super Duplex Stainless Steel

2016 ◽  
Vol 836 ◽  
pp. 165-172
Author(s):  
Suheni
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Oil And Gas ◽  
Austenite Phase ◽  
Super Duplex Stainless Steel ◽  
Shielding Gas ◽  
Input Variables ◽  
Protective Gas

Super duplex stainless steel is steel that has a corrosion resistance and good mechanical strength so that used in industry especially in oil and gas and petrochemical industry. In use in the field is often used for the connection process by welding methods. To produce good welds, it should be noted that the welding procedures and parameters used , especially the heat input. In this study is used the heat input variables shielding gas composition to determine how much influence on the balance of ferrite - austenite phase structure in the weld stainless steels SAF 2507 super duplex with tungsten inert gas welding method (TIG). Heat input varied by applying different welding speed 1,3,4 and 5 mm /sec while the shielding gas is used 100 % argon, 98 % argon + 2 % nitrogen and 95 % argon + 5 % nitrogen. The result showed that at different welding speeds generated depth and width of the weld metal which is different. Likewise the use of protective gas will produce a different ratio wide and deep of weld metal which is different. By using protective gas 95 % argon + 5 % nitrogen squeak - ausenit phase, resulting in weld metal that is relatively balanced than others. On a slow welding in addition to produce a large heat input also produces weld metal hardness at high and affect the growth of the austenite phase. The higher the heat input ( 2,280 kJ / mm ) , the lower the austenite phase in the weld metal.

scholarly journals Effect of Austenite Phase Content on Pitting Potential of a Duplex Stainless Steel

1987 ◽  
Vol 36 (10) ◽  
pp. 650-656
Author(s):  
Motoi Hara ◽  
Yutaka Shinata ◽  
Takeshi Kimura ◽  
Kokichi Hashiura
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Austenite Phase ◽  
Phase Content ◽  
Pitting Potential

Effect of heat input on the corrosion resistance of the cold worked 2304 lean duplex stainless steel GMAW welded joint

2018 ◽  
Vol 70 (3) ◽  
pp. 409-418 ◽  
Author(s):  
Carla S. Souza ◽  
Renata B. Soares ◽  
Ricardo A. D. de Faria ◽  
Alexandre Q. Bracarense ◽  
Maria das M.R. Castro ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Welded Joint ◽  
Lean Duplex Stainless Steel ◽  
Cold Worked

Microstructural and Corrosion Resistance of Lean Duplex Stainless Steel UNS S32304 Welded by SAW with Cold Wire Addition

CORROSION ◽  
10.5006/3468 ◽  
2020 ◽  
Vol 76 (7) ◽  
pp. 619-627
Author(s):  
Neice Ferreira dos Santos ◽  
Luiza Esteves ◽  
João Henrique Nery Garcia ◽  
Ronaldo Cardoso Júnior ◽  
Paulo José Modenesi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Arc Welding ◽  
Lower Amount ◽  
Lean Duplex Stainless Steel ◽  
Cold Wire ◽  
Chloride Environment ◽  
Submerged Arc

The results of the corrosion tests, in chloride environment, of lean duplex stainless steel UNS S32304 welded by submerged arc welding (SAW) process variant with cold wire, indicated that the sample with higher heat input heat input (HI) (2.7 kJ/mm) had higher corrosion resistance, which can be explained by higher amount of austenite and lower amount of precipitates. Therefore, the results indicate that the use of HI above the limit recommended by literature (2.5 kJ/mm) may produce welds with adequate corrosion resistance with SAW with cold wire addition, because this technique has the potential to deliver higher productivity still controlling the process HI.

Critical Pitting Temperature of a 22-05 Duplex Stainless Steel and Pitting Potential Statistics

2019 ◽  
Vol 16 (52) ◽  
pp. 297-305 ◽  
Author(s):  
Capucine Dussart ◽  
Lionel Peguet ◽  
Alain Gaugain ◽  
Bernard Baroux
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Pitting Potential ◽  
Critical Pitting Temperature

scholarly journals Corrosion Resistance and Mechanical Properties of TIG and A-TIG Welded Joints of Lean Duplex Stainless Steel S82441 / 1.4662

2016 ◽  
Vol 61 (2) ◽  
pp. 771-784 ◽  
Author(s):  
Z. Brytan ◽  
J. Niagaj
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Pitting Corrosion ◽  
Welded Joints ◽  
Heat Input ◽  
Filler Metal ◽  
Tig Welding ◽  
Lean Duplex Stainless Steel ◽  
Pitting Corrosion Resistance

Abstract This paper presents results of pitting corrosion resistance of TIG (autogenous and with filler metal) and A-TIG welded lean duplex stainless steel S82441/1.4662 evaluated according to ASTM G48 method, where autogenous TIG welding process was applied using different amounts of heat input and shielding gases like pure Ar and Ar+N2 and Ar+He mixtures. The results of pitting corrosion resistance of the welded joints of lean duplex stainless steel S82441 were studied in as weld conditions and after different mechanical surface finish treatments. The results of the critical pitting temperature (CPT) determined according to ASTM G48 at temperatures of 15, 25 and 35°C were presented. Three different surface treatment after welding were applied: etching, milling, brushing + etching. The influence of post weld surface treatment was studied in respect to the pitting corrosion resistance, basing on CPT temperature. Research on TIG welding of lean duplex stainless steel S82441/1.4662 showed a clear influence of the applied shielding gas mixtures, where the addition of 5 to 15% N2 to Ar virtually no effect on the level of resistance to pitting corrosion, only 5% N2 addition has a positive effect, while use of a mixture of 50% Ar + 50% He compared with welding at 100% Ar atmosphere, can significantly reduce the resistance to pitting corrosion. Definite good results were obtained during TIG welding with the participation of activation flux (A-TIG). The weld surface of lean duplex stainless S82441/1.4662 obtained in A-TIG welding without the addition of filler metal has a much lower tendency to pitting corrosion than traditional welds made by TIG method. Pitting corrosion resistance of welds made by A-TIG improved with the increase of the heat input in the tested range of welding current 100-200 A. It was also found that the intensity of the occurrence of pitting does not affect the method of cleaning welds after welding, but the mechanical removal of a thin surface layer of metal significantly reduces their intensity.

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