Modeling primary dendrite arm spacings in resistance spot welds; Part 2: Experimental studies
- Edison Welding Institute, Columbus, OH (United States)
Hold time sensitivity is a potential concern when cold-rolled high-strength low-alloy sheet steels are used in resistance spot welded applications. Hold time sensitivity is defined by cracking, which occurs along the faying surface of the weld on peel testing when conventional hold times are used, and does not occur when reduces hold times are used. Hold time sensitivity is related to solidification cracking in the steel; however, it is believed that steel hardenability may also play a role. As an aid to understanding of solidification cracking in resistance spot welds, it is necessary to have an understanding of how the solidification structure develops. In this work, solidification structures in resistance spot welds have been characterized by the primary dendrite spacing. In Part 1 of this work, primary dendrite spacings were modeled by using a combination of numerical thermal modeling and closed-form primary dendrite spacings modeling. Numerical thermal modeling was used to predict solidification conditions in these welds. These solidification conditions were then used in the primary dendrite spacings model to predict the local spacings. In this paper, experimental studies were conducted to examine the validity of the modeling described in the previous paper. Experimentally, primary dendrite spacings were characterized for three grades of cold-rolled HSLA steel with nominal compositions of 0.05C-0.3Mn, 0.1C-1Mn and 0.15C-1.5Mn. For each steel, three separate thicknesses (nominally 0.8, 1.25 and 2.0 mm) were investigated. Primary dendrite spacings were determined at nominally the weld faying surface from deep-etched micrographs using an area-averaging technique.
- OSTI ID:
- 7045579
- Journal Information:
- Welding Journal (Miami); (United States), Journal Name: Welding Journal (Miami); (United States) Vol. 73:5; ISSN 0043-2296; ISSN WEJUA3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of expulsion in spot welding of cold rolled sheet steels
Temporal pulse shaping and solidification cracking in laser welded Al-Cu alloys
Related Subjects
360101* -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CRYSTALS
DATA
DENDRITES
DISTRIBUTION
EXPERIMENTAL DATA
FABRICATION
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
JOINING
JOINTS
LOW ALLOY STEELS
MICROSTRUCTURE
NUMERICAL DATA
RESISTANCE WELDING
SPATIAL DISTRIBUTION
STEELS
WELDED JOINTS
WELDING