Assessment of rod resistivity as a test for cross-welding compatibility of various low carbon steels.

摘要

A common goal of rod producers for the wire mesh industry is to use as wide a range of chemical compositions as possible, while still meeting the required weld quality. The objectives of increased productivity and reduced cost, pressure rod producers to use wider chemical compositions for wire mesh thus incurring some risk of weld failure. The net result is that mesh producers are required to mix widely differing chemistries in their mesh applications. This introduces the risk that some of chemistries welded together by the mesh producer may be incompatible. It was hypothesized that resistivity data could improve the application of material, so we wished to test this idea.; Studied resistivity variation in relation to weld performance in a commercial welded fabric operation, five grades, 1005 to 1030 of D-2 (0.159 inches) wire and the 7/32 initial rod were tested for weld shear, weld setdown, and resistivity. Results were analyzed to assess chemistry and resistivity as a predictor of weld quality. The results of this study conclude the following: (1) Resistivity combined with carbon of the material is the best predictor of weld quality, as indicated by the setdown and weld shear strength values, with carbon being the stronger single parameter. (2) In accordance with Ohm's law and Joule's law, weld parameter settings for both quality and reduced power consumption could be better optimized by using carbon and resistivity of the material. (3) The microstructure of 1018 and 1030 wire mesh shows that welds are too hot for the carbon content with standard weld settings. As a result unfavorable martensite structure was visible. (4) The instrument used for measuring resistance of the material is very useful. To produce wire mesh from a wider range of material, it is first advised to measure the resistance of the materials and then adjust the welding parameters accordingly.