Vermicular graphite cast iron for producing brake drum of high-speed and heavy-load automobile

Abstract

The invention discloses alloyed vermicular graphite cast iron produced by alloying the ordinary vermicular graphite cast iron. The cast iron comprises an alloy of two or more of elements such as Cu, Cr, Mo, Ni, Sn, Sb, B, Ti, Al, V and the like. The vermicular graphite cast iron comprises the following chemical ingredients in percentage by weight: 3.00-3.80 percent of C, 2.00-2.80 percent of Si, 0.45-0.95 percent of Mn, less than 0.06 percent of P, less than or equal to 0.02 percent of S, and 0.02-0.60 percent of alloy ingredient. The technical indexes of the vermicular graphite cast iron are that: VG is more than or equal to 80 percent, Rm is more than or equal to 380 MPa, hardness is between 180 HBW and 258 HBW, cast pearlite is more than or equal to 60 percent, and elongation rate is between 1 percent and 2 percent. The vermicular graphite cast iron has the advantages of high intensity, high heat conductivity, high wear resistance, high thermal fatigue resistance, small deformation, simple casting process and easiness in mechanical production. The service life of a produced brake drum for a high-speed and heavy-load automobile is remarkably prolonged, and safety is ensured.

Description

technical field [0001] The invention relates to a production method of vermicular graphite cast iron. It is suitable for the production of brake drums of high-speed and heavy-duty vehicles. Background technique [0002] Existing automobile brake drums are all made of gray cast iron or low-alloy gray cast iron, but they are only suitable for general medium and low speed and medium and light-duty vehicle braking, and are far from meeting the requirements of high-speed and heavy-duty vehicle transportation. Some companies have tried to use ductile cast iron to produce automobile brake drums. Due to the defects of high elastic modulus and elongation, low thermal conductivity and small friction coefficient of ductile cast iron, the produced automobile brake drums are severely deformed during use and the brake surface cracks. The inward bulge seriously tore the brake pads, and the braking performance is poor. It is used for heavy-duty vehicles with a body weight and a load capaci...

AI Technical Summary

Problems solved by technology

The service life is more than 60 days, which is 7.5 times that of ordinary gray cast iron and nodular cast iron, 4 times that of low alloy cast iron and rare earth alloy cast iron, and 2 times that of ordinary vermicular cast iron. Serious safety hazard of car crashes