Analysis Of Factors Influencing The Surface Hardnessand Cutting Performance Of Gray Cast Iron Cylinder Head

Gray cast iron has excellent casting performance,abrasion resistance and vibration elimination performance,low notch sensitivity and good cutting performance,and is the preferred material for diesel engine cylinder head casting.With the intensification of competition in the same industry,reducing cost and increasing efficiency is the primary task for the survival and development of enterprises.For the casting industry,the mechanical properties of gray iron are an important guarantee for the reliability of the subsequent assembly and an effective measure to reduce the cost of after-sales faults.Therefore,the study of the factors influencing the surface hardness and cutting performance of gray cast iron has practical guiding significance for the whole industrial chain of the engine.Firstly,this paper analyzes the factors influencing the surface hardness of the engine gray cast iron cylinder head.Through the statistical analysis of the hardness value,graphite morphology,metallographic structure and tensile strength at different hardness positions are detected and found?1.Hot metal holding time;2.Moisture content of moulding sand;3.The amount of pig iron added;4.Aging heat treatment temperature;5.The dosage of silicon-barium inoculant.According to the field analysis,it can be determined that the burden melting must be readjusted if the holding time of molten iron exceeds 10 hours,and the aging heat treatment temperature can not be higher than 550?.However,other factors such as pig iron content,water content of moulding sand and inoculant content are also analyzed through experimental verification.Through the test at the same time,contrast the effect of hardness on the surface of a cylinder head for the amount of iron found that the increase of the proportion of cast iron will significantly reduce the surface hardness,compared the molding sand moisture content found that the increase of water content will promote form a layer of ferrite on the surface of cylinder cover layer,compared to silicon carbide smelting and changing inoculant addition amount to the influence degree of the surface hardness,found that silicon carbide is more conducive to improve surface hardness homogenization and small range.After stability control the surface hardness and the machinability of product was studied,a failure analysis as the foundation to processing difficulties,found that the influence of machinability is primarily a nitrogen content,and combining with actual production using high-quality carburant,pearlite more uniform spacing,significantly improve the subsequent processing cutting tool life.Based on the experience gained in the process of solving practical production problems,this paper conducted minitab statistical analysis on a large number of test data,providing a data-based analysis mode for the quality improvement of foundry enterprises.Because there are many factors affecting cutting,limited to the production of organizational arrangements,it is difficult to check and analyze all the factors.In this paper,the research on cutting performance is limited to the milling of casting blank surface,and there is no in-depth study on the loss of drilling tool with more feedback from machining unit.