Research On Preparing, Microstructures And Properties Of Low-alloy Steel Wear Block

Based on the low-speed, low-impact working conditions, the structure andcompound of media-carbon low-alloy wear-resistant steel are designed. The alloycntains Cr, Mn, Si, B, Ce, etc. Using View Cast casting simulation software, theoptimization of casting technique was obtained. the investment casting process ofresistance grinding blocks, including solidification and mold filling, were simulated.The austenitizing temperature810℃was determined by DTA. Hardness, impacttoughness, abrasion resistance and mechanical properties of test material after heattreatment were tested by metallurgical microscope, X-ray diffraction, TEM transmissionelectron microscopy. Impact fracture and wear morphology were tested by SEM. Theinfluence of heat treatment process on the hardness, impact toughness and wearconditions on the wear weight loss had been studied.Viewcast simulation results showed that: φ12mm×40mm ingate, φ40mm×450mm,4×4stacking sprue casting process meet the low-alloy steel wear blockcasting process requirements. It ensured the casting quality, production high efficiencyand easying to operate.Microscopic analysis showed that: low-alloy steel wear block-cast was pearlite,quenching and tempering sample was lath martensite and residual austenite, The impactfracture was quasi-cleavage fracture.The investigation of mechanical properties showed that: The hardness is up to53HRC, the impact toughness is exceeded16J/cm~2after910℃×60min oilquenching and230℃×60min tempering. With increasing quenching temperature,the hardness increased and the impact toughness decreased. When the load is constant,the wear resistance was enhanced with increasing the quenching temperature; when thewear rate is constant, the wear weight loss change with increasing temperature. Thewear weight loss quickly reduced under lubrication conditions. With increasing theabrasive，the wear resistance of the material decreased.