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      https://www.ias.ac.in/article/fulltext/sadh/028/03-04/0359-0382

    • Keywords

       

      Austenitic stainless steels; solidification cracking; composition effects; varestraint testing

    • Abstract

       

      Solidification cracking is a significant problem during the welding of austenitic stainless steels, particularly in fully austenitic and stabilized compositions. Hot cracking in stainless steel welds is caused by low-melting eutectics containing impurities such as S, P and alloy elements such as Ti, Nb. The WRC-92 diagram can be used as a general guide to maintain a desirable solidification mode during welding. Nitrogen has complex effects on weld-metal microstructure and cracking. In stabilized stainless steels, Ti and Nb react with S, N and C to form low-melting eutectics. Nitrogen picked up during welding significantly enhances cracking, which is reduced by minimizing the ratio of Ti or Nb to that of C and N present. The metallurgical propensity to solidification cracking is determined by elemental segregation, which manifests itself as a brittleness temperature range or BTR, that can be determined using the varestraint test. Total crack length (TCL), used extensively in hot cracking assessment, exhibits greater variability due to extraneous factors as compared to BTR. In austenitic stainless steels, segregation plays an overwhelming role in determining cracking susceptibility.

    • Author Affiliations

       

      V Shankar1 T P S Gill1 S L Mannan1 S Sundaresan1 2

      1. Indira Gandhi Centre for Atomic Research, Kalpakkam - 603 102, India
      2. Department of Metallurgical Engineering, Indian Institute of Technology -Madras, Chennai - 600 036, India
    • Dates

       
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