Research On Processing Performance Of High-strength Gray Cast Iron After Different Inoculation

Gray iron casting materials have good formability, machinability, wear resistance, heatresistance, shock-absorbing properties, etc., which make them be a traditional metal structurematerials and occupy an important position in foundry production. At present, gray ironcastings account for the weight of the first of kinds of castings (about 50% ~ 55%). As marketcompetition intensifies, gray cast iron is a traditional metal structural material of wide largequantity, but also faces with a serious challenge of the quality, performance and price ofmaterials. Gray cast iron still has a certain degree of competitiveness, because of overcomingits low matrix strength weakness, now gray iron castings is to meet the tensile strength of250MPa. Certain parts of large trucks (such as high-powered diesel engine cylinder block)select materials other than gray cast iron. With the gray iron castings to improve strength ofthe matrix, such a problem comes, with the improvement of its tensile strength, the pearlitematrix to improve the content, processing performance of medium and high-intensity graycast iron have shown a downward trend..In recent years, with continuous researches on high strength gray cast iron castings,mechanical properties of block of gray iron castings manufactured by many companiesachieves the same level abroad, are in line with performance requirements, and exploitsChinese-made high-strength gray cast iron cylinder block of high-powered diesel engine withindependent intellectual property rights. However, there is still a large gap between thedomestic auto industry and foreign advanced level. The efficiency of processing of thedomestic high-strength cylinder block, cylinder head and cylinder block is 40% to 80% of imported cases, and greatly improves productivity costs. By 2008, China FAW GroupCorporation production was 150,000 heavy-duty trucks, heavy-duty trucks of the nationalproduction will reach 300,000. At present, FAW Group Corporation of high-powered castengine block casting production line is pre-production, FAW Dalian Diesel Engine Factoryand Wuxi Diesel Engine Factory is ready to produce more than 350 horsepower diesel engine,it can be seen that its market demand is growing and has a bright future with the rapiddevelopment of auto industry. Facing with the blockade of foreign advanced technology otour country, as well as the domestic voice to improve casting's processing, research onimproving the casting process is very necessary.This study based on composition and the melting process optimized by the FAW GroupCasting Institute with Jilin University, used the self-developed JF series compositemetamorphic iron-treated solution, develops a new type of carbon-equivalent non-Mo highstrengthgray cast iron successfully. And by studying the JF series composite Modificator'seffects on pearlitic gray cast iron, graphite and the effects of eutectic Mission, explores theperformance of the processing factor, obtains the excellent mechanical properties and higherperformance processing of high-yield high-strength gray cast iron. In this paper, the effects ofdifferent breeds Modificator on gray cast iron cutting force, tool wear, workpiece surfacequality table is studied, by analyzing the experimental results showed that:(1) Adding the current production of 0.45% JF-1 composite metamorphic-treated highstrengthgray cast iron elements and adding Mo organizations compared to imported materials,both the number of graphite are almost the same, but graphite of sample B is smaller, thecontent is relatively low, it is not conducive to cutting performance; as to pearlite areas, Bchipsample spacing of pearlite is smaller, so the microhardness of pearlite is higher, inaddition to cementite films are relatively thick, which affects the processing performance ofthe B sample, processing performance of metamorphic-treated high-strength gray cast ironadding 0.45% JF-1 composite is inferior to foreign materials containing Mo.(2) By adjust the added volume of JF-1 complex, it is found that processing performance ofC sample of high-strength gray cast iron metamorphic-treated by adding 0.35% JF-1compound modification is better than B, D samples metamorphic-treated by adding 0.45% JF-1, 0.60% JF-1 composite. The reason for this conclusion appearance is that there are Si,RE, N, V and Fe elements in the JF-1 compound modifier. These elements in a suitedproportion promote each other, and can be able to get a better organization and performance,However, when changes to content, due to the amount of modifier changes, the interaction ofvarious elements reunites to form a hard mass, or decomposes and fails to achieve the role inthe formation of nuclei, thus does not effective metamorphism and even worse performance.(3) The life of C sample tools treated by adding 0.35% JF-1 compound modification isloner than foreign high-strength gray cast iron A sample which with elements Mo, but theworkpiece has poor surface quality.(4) After adding different content of JF-2 do step modifier improved, it can be obtained thatF sample is superior to foreign high-strength gray cast iron A sample which with elements Moin the mechanical properties, tool life and workpiece surface quality, and can be completelyreplace imported material in order to reduce costs.