Indian Welding Journal

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Solidification Behavior of Duplex Stainless Steel (UNS S32205) Welds as a Function of WRC–1992 Diagram Equivalents and Cooling Rate


Affiliations
1 Metallurgy Department, Government Engineering College, Sec-28, Gandhinagar, Gujarat, India
2 Metallurgical and Materials Engineering Department, The M.S. University of Baroda, Vadodara, Gujarat, India
     

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Duplex stainless steels solidify as 100 % Ferrite, however solidification of Duplex Stainless steel welds is a function of Chromium equivalent and Nickel equivalent alloying elements, filler metal and base metal composition and associated weld thermal cycle. Resultant solidification mode behavior and hence final weld metal microstructure is always a matter of interest among researcher because mechanical properties and corrosion properties are depending on weld metal ferrite content. The present research is to investigate the solidification mode behavior of duplex stainless steel welds with varying Chromium equivalent and Nickel equivalent ratios and associated weld cooling rate. In order to meet this objective, weld coupon were prepared using experimental Low Nickel, Medium Nickel and High Nickel electrodes using SMAW process, step wise increased in Nickel content from commercially available standard 09 weight percentage Nickel in E2209 design. WRC-1992 Diagram has been used to calculate Chromium Equivalent and Nickel equivalent and predict Ferrite Number using compositions of Base metal and Nickel enriched experimental electrodes. Microstructure characterization of all weld coupons is carried out using ASTM A 923 Method. Calculated values were correlated with the different microstructures developed. According to the findings of the studies, weld produced with higher Nickel content electrode, when cooled with maximum rate approximately 100.8 °C/ Sec , considered under study, exhibited FA-mode of solidification with as low as 1.71 Creq/Nieq ratio and there was no noteworthy presence of intermetallic phases and precipitations in as-weld microstructures at approximate retained ferrite level of 15 Ferrite Number.

Keywords

Duplex Stainless Steel, Ferrite Number, Cooling Rate, Solidification Mode, WRC-1992 Diagram, Chromium Equivalent, Nickel Equivalent.
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  • API Technical report 938-C (2015); Use of duplex stainless steels in the oil refining industry, 9th Edition, pp.2-7.

  • Lippod JC and Kotecki D J (2005); Welding Metallurgy & Weldability of Stainless Steels, John Wiley and Sons, pp.234- 262

  • Kotecki DJ and Siewert TA (1992); WRC-1992 constitution diagram for stainless steel weld metals: a modification of the WRC-1988 diagram, Welding Journal, 71(5), pp. 171-s-178-s.

  • Kou S (2003); Welding Metallurgy, John Willey, 2nd Edition, USA, pp- 55-56

  • Adams C. M. Jr. (1958); Cooling rates and peak temperatures in fusion welding, Welding Journal, 37(5), pp.210-s-215s

  • Jhaveri P, Moffatt WF and Adams Jr. CM (1962); Effect of plate thickness and radiation on heat flow in welding and cutting, Welding Journal, 41(1), pp.12-s-16-s

  • Welding Handbook, American Welding Society, 2087, 8th Edition, Vol. 1, USA, pp.99-105.

  • IMOA (2001); Practical Guidelines for the Fabrication of Duplex Stainless Steels, Revised Edition, International Molybdenum Association, USA. pp.14-17.

  • http://www.matweb.com/search/datasheet.aspx?matguid=000b4e364a7d41b78d23ea8ede78491e &ckck=1

  • Xavier CR, Guimarães H, Junior D and de Castro JA (2015); An experimental and numerical approach for the welding effects on the duplex stainless steel microstructure, Materials research, DOI: http://dx.doi.org/10.1590/1516-1439.302014.

  • Kotecki D J (1986); Ferrite control in duplex stainless steel weld metal, Welding Journal, 65(10), pp.273s-278s.

  • ASTM A800/ A800M- 14, Standard Practice for Steel Casting, Austenitic Alloy, Estimating Ferrite Content Thereof.

  • ISO 8249:2000, Welding- Determination of Ferrite Number (FN) in Austenitic and Duplex Ferritic-Austenitic Cr-Ni Stainless Steel Weld Metals.

  • ASTM A 923 Standard Practices for Detecting Intermetallic Phases in Duplex Austenitic/ Ferritic Stainless Steel, ASTM International, West Conshohocken, PA

  • Kotecki DJ (2013); A Guide for Troubleshooting Stainless Steel Welding-Related Problems: Welding Stainless SteelQuestions and Answers, AWS Publication, 1st Edition, pp.172-173.73


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  • Solidification Behavior of Duplex Stainless Steel (UNS S32205) Welds as a Function of WRC–1992 Diagram Equivalents and Cooling Rate

Abstract Views: 486  |  PDF Views: 5

Authors

Purvesh K. Nanavati
Metallurgy Department, Government Engineering College, Sec-28, Gandhinagar, Gujarat, India
Sanjay N. Soman
Metallurgical and Materials Engineering Department, The M.S. University of Baroda, Vadodara, Gujarat, India

Abstract


Duplex stainless steels solidify as 100 % Ferrite, however solidification of Duplex Stainless steel welds is a function of Chromium equivalent and Nickel equivalent alloying elements, filler metal and base metal composition and associated weld thermal cycle. Resultant solidification mode behavior and hence final weld metal microstructure is always a matter of interest among researcher because mechanical properties and corrosion properties are depending on weld metal ferrite content. The present research is to investigate the solidification mode behavior of duplex stainless steel welds with varying Chromium equivalent and Nickel equivalent ratios and associated weld cooling rate. In order to meet this objective, weld coupon were prepared using experimental Low Nickel, Medium Nickel and High Nickel electrodes using SMAW process, step wise increased in Nickel content from commercially available standard 09 weight percentage Nickel in E2209 design. WRC-1992 Diagram has been used to calculate Chromium Equivalent and Nickel equivalent and predict Ferrite Number using compositions of Base metal and Nickel enriched experimental electrodes. Microstructure characterization of all weld coupons is carried out using ASTM A 923 Method. Calculated values were correlated with the different microstructures developed. According to the findings of the studies, weld produced with higher Nickel content electrode, when cooled with maximum rate approximately 100.8 °C/ Sec , considered under study, exhibited FA-mode of solidification with as low as 1.71 Creq/Nieq ratio and there was no noteworthy presence of intermetallic phases and precipitations in as-weld microstructures at approximate retained ferrite level of 15 Ferrite Number.

Keywords


Duplex Stainless Steel, Ferrite Number, Cooling Rate, Solidification Mode, WRC-1992 Diagram, Chromium Equivalent, Nickel Equivalent.

References





DOI: https://doi.org/10.22486/iwj%2F2019%2Fv52%2Fi2%2F181777