Classification of heat treatment for precision casting of carbon steel foundry
Due to precision casting,Carbon steel precision castingThe intention is different. There are many quenching and tempering treatments, and the essence can be divided into two types. The first type is that the distribution structure is not easy to undergo tempering treatment and the disease transformation may not be modified. The second is the essential distribution structure. The first quenching and tempering process is mainly used to remove thermal stress, and this thermal stress is caused by different water cooling conditions and standards during the whole process of stainless steel casting. Distribution, compressive strength, and other mechanical equipment characteristics, etc., will not change significantly due to quenching and tempering treatment.
Regarding the second quenching and tempering treatment of precision casting in carbon steel foundries, the distribution of industrial bases has undergone significant changes, which can be roughly divided into five categories:
1. Softening and quenching: Its purpose mainly depends on splitting martensite, reducing its strength, and developing production and processing functions. Regarding malleable cast iron, its purpose depends on obtaining a large amount of metallographic structure distribution.
2. Normalizing treatment: The main purpose is to obtain the distribution of ferrite and sorbite to develop the mechanical equipment of stainless steel casting.
3. Heat treatment solution: mainly in order to obtain higher strength or friction coefficient compressive strength, together with very high surface wear resistance characteristics.
4. The surface hard bottoming solution: mainly to obtain the surface hard bottoming layer, together to obtain very high surface wear resistance characteristics.
5. Precision casting is separated from the hard bottom to solve: mainly to obtain high toughness and the elongation is not a strong modification of the disease.
Carbon steel precision casting uses:
(1) Carbon steel can be divided into three categories: carbon structural steel, carbon tool steel and free-cutting structural steel according to its purpose. Carbon structural steel is further divided into engineering construction steel and machine-manufactured structural steel;
(2) According to the smelting method, it can be divided into open hearth steel and converter steel;
(3) According to the deoxidation method, it can be divided into boiling steel (F), killed steel (Z), semi-killed steel (b) and special killed steel (TZ);
(4) Carbon steel can be divided into low carbon steel (WC ≤ 0.25%), medium carbon steel (WC0.25%—0.6%) and high carbon steel (WC> 0.6%) according to the carbon content;
(5) According to the quality of steel, carbon steel can be divided into ordinary carbon steel (higher phosphorus and sulfur), high-quality carbon steel (lower phosphorus and sulfur) and high-grade high-quality steel (lower phosphorus and sulfur). ) And super high-quality steel.