Introduction to the correct annealing method of ball milled cast iron

- Dec 17, 2020-

There are some problems to pay attention to when using ball milled cast iron, that is, the problem of annealing. How should annealing be done? Let me give you a detailed introduction.

It is understood that the comprehensive properties of ball-milled cast iron are close to steel, and it has developed into a cast iron material second only to gray cast iron and widely used. Due to its excellent properties, ball-milled cast iron can sometimes replace cast steel and forged steel in use, and is widely used in the machinery manufacturing industry.

The annealing heat treatment of ball milled cast iron is to improve the overall performance of cast iron. Common processes include annealing, normalizing, and quenching. Nodular graphite castings as bearings require higher hardness, and iron castings are often quenched and tempered at low temperatures. The specific method is to heat the casting to a temperature of 860-900℃, keep the original matrix completely austenitized, then cool it in oil or molten salt to achieve quenching, and then heat it at 250-350℃, heat preservation and tempering, the original matrix is transformed into After tempering martensite and retained austenite, the original spheroidal graphite remains unchanged.