Deoxidized steel is steel which has some or all of the oxygen removed from the melt during the steelmaking process. Molten steel contains dissolved oxygen after being converted from molten iron, but the solubility of oxygen in steel decreases with cooling. As the steel cools, excess oxygen can cause pores or precipitate FeO. This results in cleaner, better quality steel with fewer air pockets and inclusions. Deoxidized steel, can be divided into four types: killed steel, semi-killed steel, rimmed steel, and capped steel.
General killed steel includes alloy steel, stainless steel, and heat-resistant steel. Steels with a carbon content greater than 0.25%, steels used for forgings, structural steels with a carbon content between 0.15 and 0.25%, and some special steels in the lower carbon ranges.It is also used for any steel castings.
Killed steel has a more uniform chemical composition and properties than semi-killed and edge steels. Killed steel is generally harder than edge steel for a given carbon and manganese content. The disadvantage of killed steels is that they often exhibit deep tube contraction.
ASTM A106, Standard Specification for Carbon Steel Pipe Made of Killed Steel for High Temperature Applications. ASTM A106 Grade B allows higher carbon and manganese content ASTM A106 Grade A. ASTM A333, this specification covers seamless and welded carbon and alloy steel pipe for cryogenic service, known as killed carbon steel.
