As-cast gray cast iron braking material with low alloy content and high thermal fatigue strength

Abstract

The invention relates to the field of casting and discloses an as-cast gray cast iron braking material with low alloy content and high thermal fatigue strength. The as-cast gray cast iron braking material with low alloy content and high thermal fatigue strength comprises the following chemical components in percentage by weight: 3.5-3.7% of C, 1.6-2.0% of Si, 0.7-1.0% of Mn, 0.15-0.3% of Cu, 0.2-0.3% of Cr, 0.015-0.02% of Sb, 0.018-0.02% of Sn, not more than 0.08% of P, not more than 0.07% of S and the balance of Fe. A production method comprises the steps of: putting cast iron Q10 or Q12, waste steel, foundry returns and ferromanganese iron No. 60 in proportion as required into a cupola furnace for smelting, adding Cr and Sb alloy in certain proportion in a tapping water tank, adding silicon iron No. 75 and Sn and Cu alloy into a foundry ladle, performing primary inoculation and alloying on smelted molten iron, adding a composite inoculant into a casting ladle, performing secondary ladle-to-ladle inoculation, and pouring into a prefabricated sand mould for molding and cooling to obtain a product as required. Due to adoption of the technical scheme, materials are improved, the performance of a brake drum is enhanced and the production cost is reduced.

Description

technical field [0001] The invention relates to the field of casting, and relates to a gray cast iron braking material with low alloy and high thermal fatigue strength in as-cast state. technical background [0002] In production practice, common automobile brake drum materials are HT200, HT250, HT300 or modified gray cast iron materials with Cu and Cr alloys added to them. However, in the actual use process, due to the common phenomenon of automobile overloading in our country, and the uneven roads in the mining area, the mountains are high and the roads are steep, the damage to the brake drum is particularly large. Frequent braking or long-term braking, the temperature of the brake drum can reach more than 600 ° C, and in actual use, the method of spraying water to the brake drum is used to cool down, which accelerates the early failure of the brake drum. According to statistics, the early failure rate of heavy-duty vehicle brake drums reaches 15-20%. Due to the limitati...

AI Technical Summary

Problems solved by technology

Frequent braking or long-term braking, the temperature of the brake drum can reach more than 600 ° C, and in actual use, the method of spraying water on the brake drum is used to cool down, which accelerates the early failure of the brake drum