时间：2014-03-06 20:13　作者：admin　点击： 次

Cast steel is an alloy with iron and carbon as the main elements, with a carbon content of 0 to 2%, and is used for pouring castings.Cast steel is divided into cast carbon steel, cast low alloy steel and cast special steel.
Steel castings should be used after heat treatment.Because there are casting defects such as porosity, cracks, shrinkage cavity and shrinkage porosity, coarse grains, uneven structure and residual internal stress in the steel castings in the as-cast state, the strength, especially the plasticity and toughness of the steel castings are greatly reduced.
In order to refine the grain, uniform structure and eliminate internal stress, steel castings must be normalized or annealed.Normalized steel has higher mechanical properties and lower cost than annealed steel, so it has more applications.However, because normalizing treatment will cause larger internal stress than annealing, it is only suitable for steel castings with a carbon content of less than 0.35%.Because low-carbon steel castings have good plasticity, they are not easy to crack during cooling.In order to reduce internal stress, steel castings should be tempered at high temperature after normalizing.For steel castings with carbon content ≥.35%, complex structure and easy to crack, only annealing treatment can be carried out.Steel castings should not be quenched, otherwise they will easily crack.
Advantages of steel castings:
1. Greater design flexibility: This design has the greatest freedom to choose the shape and size of the casting, especially the complex shape and hollow part, and the steel casting can be manufactured by the unique process of the core casting.Easy to shape and change shape, and can quickly produce finished products according to drawings, which can provide quick response and shorten delivery time.
2. The strongest flexibility and variability in metallurgical manufacturing: you can choose different chemical compositions and organizational structures to meet the needs of different projects.Different heat treatment processes can select mechanical properties and can use this property in a wide range and improve solderability and usability.
3. Improve the overall structural strength: Due to the high reliability of the project, coupled with the weight reduction design and short delivery time, it can increase the competitive advantage in terms of price and economy.
4. A wide range of weight changes: small steel castings may be only 10 grams, while large steel castings can reach several tons, dozens or even hundreds of tons.