CHARACTERISTICS OF LAMELLAR TEARING IN WELDED STEEL

Lamellar tearing is a form of cracking that occurs in the base metal of weldments due to the combined effects of the anisotropic characteristics of hot rolled steel and the high stresses generated by weld thermal contraction acting perpendicular to the rolling plane. This cracking is most commonly associated with highly restrained tee or corner joints where the weld fusion boundary is parallel to the rolling plane of the section. The morphology of a lamellar tear is characterized by terrace fracture surfaces parallel to the rolling plane joined in a step-like manner by shear-wall fractures nearly perpendicular to the rolling plane. Initiation of the terrace fractures is shown to be associated with elongated or aligned inclusions, which tend to decohere and reduce the through-thickness ductility of rolled steel. It is only in the last ten years that designers, materials engineers, and welding engineers have become actively concerned with the problem of lamellar tearing and its solution, a problem that has been exacerbated by the need for thicker sections and higher strength steels. Since the interaction of material factors and welding procedures in causing tearing is not well understood, it was decided to develop a weldability test for evaluating the susceptibility of steels to lamellar tearing and to examine some of the characteristics of the phenomenon. (A)

• Corporate Authors:

  Australian Welding Institute

  118 Alfred Street
  Milsons Point, Milsons Point,   Australia 
• Authors:
  • Stout, R D
• Publication Date: 1976

Language

• English

Media Info

• Features: Figures; Tables;
• Pagination: v.p.

Subject/Index Terms

• TRT Terms: Conferences; Cracking; Ductility; Fracture mechanics; Fusion; Heat; Isotropy; Properties of materials; Sensitivity; Shrinkage; Steel; Strength of materials; Stresses; Surfaces; Tearing; Tests; Thickness; Welding; Weldments
• Uncontrolled Terms: Steel beams; Weldability
• Old TRIS Terms: Drivometer; Lamellar structure
• ITRD Terms: 8525: Conference; 5211: Cracking; 5909: Ductility; 5270: Fusion; 6743: Heat; 5917: Isotropic; 5925: Properties; 5928: Sensitivity; 4743: Shrinkage; 4542: Steel; 5544: Strength (mater); 5575: Stress (in material); 6438: Surface; 6255: Test; 5933: Thickness; 3852: Welding
• Subject Areas: Geotechnology; Highways; Materials; I34: Steels and Metals;

Filing Info

• Accession Number: 00164346
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Report/Paper Numbers: Analytic
• Files: ITRD, TRIS
• Created Date: Apr 12 1978 12:00AM