Chrome molybdenum vermicular graphite cast iron non-cracking brake drum of high thermal fatigue resistance performance and production process thereof

Abstract

The invention discloses a chrome molybdenum vermicular graphite cast iron non-cracking brake drum of high thermal fatigue resistance performance and a production process thereof. The production process comprises the steps of adding 0.40 percent-0.80 percent of ferrochrome and 0.40 percent-1.20 percent of ferrochrome to common vermicular graphite cast iron base iron according to the weight ratio, smelting the vermicular graphite cast iron base iron, performing vermicular inoculation on the vermicular graphite cast iron base iron to obtain chrome molybdenum vermicular graphite cast iron final molten iron, pouring the chrome molybdenum vermicular graphite cast iron final molten iron, cooling and cleaning a poured casting to obtain a chrome molybdenum vermicular graphite cast iron brake drum casting, performing complete austenitizing normalizing treatment on the chrome molybdenum vermicular graphite cast iron brake drum casting at the temperature ranging from 900 DEG C to 950 DEG C by keeping the temperature for 1.0-1.2 hours, machining the chrome molybdenum vermicular graphite cast iron brake drum casting after the chrome molybdenum vermicular graphite cast iron brake drum casting is discharged out of a furnace and cooled down, and checking out the chrome molybdenum vermicular graphite cast iron brake drum casting to obtain the chrome molybdenum vermicular graphite cast iron non-cracking brake drum of high thermal fatigue resistance performance if the chrome molybdenum vermicular graphite cast iron brake drum casting is qualified. By means of the production process, the brake drum of a heavy-load vehicle is durable and unlikely to crack to ensure transportation safety.

Description

technical field

[0001] The invention relates to the technical field of automobile brake drums, in particular to a chrome-molybdenum vermicular graphite cast iron non-crack brake drum with high thermal fatigue resistance and a production process thereof. Background technique

[0002] Most of the existing automobile brake drums are produced by traditional gray cast iron or low-alloy gray cast iron, which are only suitable for general medium and low speed and medium and light-duty vehicle braking, and are far from meeting the requirements of heavy-duty vehicle transportation. Some domestic enterprises use ordinary vermicular graphite cast iron to produce brake drums. Due to the low strength and hardness of ordinary vermicular graphite cast iron and high elongation, the brake drums are severely deformed during use. The cracks protrude inward, causing serious tearing of the brake pads, and the service life is equivalent to that of low-alloy gray cast iron brake drums.

[0003] T...