There is cracking failure at the weld seam of high strength and toughness 490CL wheel steel rim made with flash butt welding during flaring and forming process. Its causes are analyzed through macroscopic and microscopic observations of fracture morphology,tests of chemical compositions,mechanical properties,microstructure and microhard-ness as well as energy spectrum composition analysis. The results indicated that there were certain area of welding"gray spots"mainly composed of manganese oxide at weld failure so that the weld ductility was reduced. As a result,there is cracking at weld fusion line during flaring and forming process of welded rim. The weld quality of 490CL wheel steel for rim is improved by adjusting such welding parameters as reducing flash allowance and increasing pressure of upset forging so that the proportion of weld failure during forming of rim is reduced from 1. 5％ to 0. 3％.
维普
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