Study On The Leakage Of The Cast Iron Based On The Engine Cylinder Body

The thesis is based on the production of cylinder body and head of Jianghuai automobile company.After studying the Influence factor, rule and the prevention measure of the leakage flaw,we get the following results:Through to the leakage statistics, the leakage flaw mainly occurs in the casting hot festival spot, like water jacket core close neighbor's bolt hole place, oil lead and water jacket, but the latter two institutes account for the leakage proportion to be very small.The flaw occurred in the bolt hole place leakage is accounts for the very great proportion. In the bolt hole place leakage flaw is because shrinks the pine to cause.The Pouring temperature obviously affect The Liquid state shrinkage. After analysis,we find the that the casting leakage rate elevates along with pouring temperature's unceasing increment, The tendency rejection rate which increases along with temperature increment slightly has reduces when the pouring temperature is above 1400℃.Overall evaluation each factor, the pouring temperature will decide as 1410～1420℃.The breeding craft is also affects the leakage intensely.The influence of the different type's inoculant to the leakage is different. The increase of the inoculant will cause leakage rejection rate increase. After massive experiments and analysising the experimental result, We finally decided that the quantity of the inoculant is 0.4%, the Si-Ba inoculant and the 75Si-Fe inoculant occupy half respectively.Trace element Pb will also have the very tremendous influence to the leakage.After studying the sample the Pb quantity of the loose area is obviously higher than the compact area which close neighbor to the loose area. Pb intense change graphite shape, the leakage rejection rate presents the obvious trend of escalation along with its content's unceasing increase. Therefore we should strict control the content of the element Pb.In the iron liquor chemical composition, Cr and C influence the leakage most remarkably, Cr is one kind of higdered graphite element, Its intense impede graphite separation, but the quantity of the C height immediate influence graphite separation. Therefore we should reduce Cr as far as possible, but total carbon between 3.30～3.35 %and control the Si/C nearby 0.64,The iron liquid forms the compact metal organization, thus reduced leakage flaw formation.