Vermicular graphite cast iron for break disc of high-speed/heavy-duty vehicle

Abstract

The invention discloses a vermicular graphite cast iron for the break disc of a high-speed / heavy-duty vehicle. The vermicular graphite cast iron comprises 0.30 to 0.60 percent of molybdenum, 0.40 to 1.00 percent of nickel, 3.30 to 3.60 percent of carbon, 2.20 to 2.50 percent of silicon, 0.20 to 0.55 percent of manganese, 0 to 0.040 percent of phosphorus, 0 to 0.025 percent of sulfur, 0.020 to 0.035 percent of rare earth, 0.010 to 0.020 percent of magnesium and the balance of iron; the creep ratio is controlled to range from 55 to 85 percent, the pearlite content is controlled to range from 35 to 75 percent, and the tensile strength is equal to or larger than 400 MPa. The vermicular graphite cast iron has the characteristics of high strength, good high temperature performance, high heat-resisting fatigue performance and high wear resistance during operation in an extremely hot or cold harsh environment, and greatly prolongs the service life of the break disc of the high-speed / heavy-duty vehicle. The vermicular graphite cast iron is simple in production process; the break disc of the high-speed / high-duty vehicle has the advantages of light weight, stable braking and long service life and is applicable to various sedans, medium and large buses, and heavy-duty trucks.

Description

technical field [0001] The invention relates to the technical field of metal materials for automobile brake discs, in particular to a vermicular graphite cast iron used for high-speed / heavy-duty automobile brake discs. Background technique [0002] The existing brake discs are mainly made of aluminum alloy, low alloy gray cast iron and nodular cast iron. The aluminum alloy brake disc has the characteristics of light weight and good heat dissipation performance, but has the disadvantages of low strength and low wear resistance; low alloy gray cast iron brake The disc has the characteristics of good heat dissipation performance, but it has the disadvantages of low strength, low thermal fatigue resistance, low wear resistance and heavy weight; nodular cast iron brake disc has the characteristics of high strength, high wear resistance and high thermal fatigue resistance. However, there are disadvantages of low heat dissipation performance and small friction coefficient. Due to t...

AI Technical Summary

Problems solved by technology

[0002] The existing brake discs are mainly made of aluminum alloy, low alloy gray cast iron and nodular cast iron. The aluminum alloy brake disc has the characteristics of light weight and good heat dissipation performance, but has the disadvantages of low strength and low wear resistance; low alloy gray cast iron brake The disc has the characteristics of good heat dissipation performance, but it has the disadvantages of low strength, low thermal fatigue resistance, low wear resistance and heavy weight; nodular cast iron brake disc has the characteristics of high strength, high wear resistance and high thermal fatigue resistance. However, there are disadvantages of low heat dissipation performance and small friction coefficient. Due to the small friction coefficient, the brakes cannot be stopped, and there is a great potential safety hazard.

[0003] Application No. 201110350420.9 "A Brake Disc and Its Preparation Method" uses low-alloy gray cast iron to produce brake discs, which have the disadvantages of low strength, low thermal fatigue resistance, low wear resistance, and heavy weight

[0004] Application No. 2009102295336 "A Ductile Iron for Heavy-Duty Truck Brake Disc" uses low-alloy ductile iron to produce brake discs, which has the disadvantages of low heat dissipation and small friction coefficient. Due to the small friction coefficient, the brake cannot be stopped, and there is a huge Security risks

[0005] Tests carried out in application number 001110349 "Carbon / carbon composite brake discs" have shown that this application sometimes leads to unwanted increases in vibration and often irregular increases in braking torque

[0006] Application No. 961804491 "Manufacture of Brake Disc Composite Fabric Disc Material" has a cumbersome manufacturing process and is not suitable for mass production on mechanized and automated assembly lines