Relationship Between Cracks in Steel Castings And Inclusions in Steel

One of the important reasons for the cracks of steel castings is the inclusion of molten steel in the smelting process.

The inclusions in steel mainly refer to the non-metallic inclusions in steel. The non-metallic inclusions in steel come from two aspects: first, they are generated with the smelting process, that is, the deoxidation products of ferroalloy added during tapping and the secondary oxidation products of molten steel and air during pouring, which are called endogenous inclusions. Such inclusions are generally fine particles and evenly distributed in the steel; Second, it is brought in from the outside for various reasons, which is called foreign inclusions. These inclusions are mostly irregular in shape, large in size and uneven in distribution. They are the main reason for cracks and are harmful to steel.

In order to reduce the inclusions in the molten steel, during the smelting process, it is necessary to strengthen the smelting operations such as deoxidation, desulfurization, impurity removal and degassing, and take necessary measures in the ladle behind the furnace, such as adding rare earth to modify the shape of the inclusions, so as to reduce the presence of inclusions and better eliminate the cracks of the steel castings.