The internal defects in cross wedge rolling process are a big issue restricting the widely use of the technology in industry. Although internal failures in cross wedge rolling have been investigated by several authors, the internal defect generation and effective parameters are still not completely clear. In this study, the internal fracture of 1045 steel railway sleeper crew during cross wedge rolling were investigated numerically by using Johnson-Cook fracture model. Based on analyzing the relationship between stress and strain in the deformed area, the mechanisms of internal fracture of sleeper screw during cross wedge rolling process was explained and made clear. The simulation results are in reasonable agreement with experimental results conducted at the same conditions.
This study the AZ31 magnesium alloy trips of the dimension 60×60×3 mm was used for constrained groove pressing (CGP) after 4 cycles under elevated temperature condition. Microstructure and mechanical properties were analyzed for a material with ultra-fine grained structure prepared by CGP of AZ31 magnesium alloy. Analysis of the scanning electron microscope (SEM) micrographs observations showed significant drop of the grain size from (50 ÷ 60) μm to (4 ÷ 6) μm after four CGP cycles. The minimal grain size of (H1.5) μm was detected in the regions of the highest deformation. Moreover, the tensile test along the x and z directions showed excellent high strength (325 MPa) and also plastic elongation of 35 %. It is shown that the CGP technique is a good tool for the grain refinement and improving mechanical properties of magnesium alloys.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.