A STUDY OF NOTCH TOUGHNESS AND WELD SOFTENING IN SUBMERGED-ARC WELD HEAT-AFFECTED ZONE FOR Q&T HIGH TENSILE STEEL (REPORT 3) (EFFECT OF ALLOYING ELEMENTS ON NOTCH TOUGHNESS AND WELD SOFTENING IN SINGLE-PASS SUBMERGED-ARC WELD HEAT-AFFECTED ZONE)

Experimental studies were made on the effect of alloying elements on the notch toughness of single-pass submerged-arc weld bond and weld softening in heat-affected zone welded with comparatively large heat input, employing 2 mm V notch Charpy impact test and small size tensile test of a systematically prepared 80 kg/sq. mm high tensile steel plate. Notch toughness of weld bond diminished with the increase of heat input. Alloying elements which reduce notch toughness of weld bond are carbon, nitrogen, boron and large quantities of titanium. Reducing the carbon content to less than 0.10 percent improves the notch toughness of weld bond greatly. Alloying elements which improve the notch toughness of weld bond are nickel, silicon and small quantities of vanadium. Increasing aluminum decreases the notch toughness of weld bond, but the results are quite contrary to those of duplicated weld heat-affected zone. Manganese, chromium and molybdenum have a slight influence on notch toughness of weld bond, presumably because of bainitic structure in weld bond. Niobium up to 0.05 percent also has little effect on the notch toughness of weld bond. Alloying elements which reduce weld softening are carbon, niobium, vanadium, chromium, molybdenum, nitrogen, aluminum, phosphorus and adequate quantity of silicon. Tensile strength of softened heat-affected zone is generally improved with the addition of secondary hardening elements. Microstructures of weld bond were upper bainitic and no primary ferrite was found, but a complete lower bainitic structure was hard to obtain in weld bond with the highly hardenable steels tested. In Japanese.

• Corporate Authors:

  Japan Welding Society

  1-11, Sakuma-cho, Kanda, Chiyoda-ku
  Tokyo,   Japan 
• Authors:
  • Sato, M
  • Nakasugi, H
• Publication Date: 1971

Media Info

• Pagination: p. 55-71
• Serial:
  • Japan Welding Society, Journal of
  • Volume: 40
  • Issue Number: 6
  • Publisher: Japan Welding Society

Subject/Index Terms

• TRT Terms: Metal heating; Notching (Cutting); Strength of materials; Welds
• Uncontrolled Terms: Heat treatment
• Old TRIS Terms: Notch toughness; Weld properties
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00032634
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Files: TRIS
• Created Date: Apr 21 1972 12:00AM