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HIGH STRENGTH SPRING STEEL
HIGH CARBON STEEL
High carbon steels are steels with high carbon contents. Asia Industrial Metals supplies high carbon steels with carbon contents from 0.5% up to 1.25% in term of weight, in form of strip (coiled narrow band), with dimensional range.
- Thickness: 0.05mm up to 0.8mm
- Width: 5mm up to 600mm
BASIC CONCEPT OF HIGH CARBON STEEL
What are high carbon steels?
High carbon steels are steels with high carbon contents. Asia Industrial Metals supplies high carbon steels with carbon contents from 0.5% up to 1.25% in term of weight. And Asia Industrial Metals only supplies high carbon steels in form of strip (coiled narrow band).
Normally carbon steels can be classified as Low carbon, Medium carbon, High carbon, and Ultra-High carbon steels as following.
- Low-carbon steel: 0.05 to 0.25% carbon
- Medium-carbon steel: Approximately 0.3–0.5% carbon content.
- High-carbon steel: Approximately 0.6 to 1.0% carbon content.
- Ultra-high-carbon steel: Approximately 1.25–2.0% carbon content.
At Asia Industrial Metals, we focus on carbon steels with carbon contents from 0.5% up to 1.25%. And we just classify them as high carbon steel for convenience’s sake.
Type or Grade of High Carbon Steel
Japan JIS specification
S50CM, S60CM, S65CM, S70CM, SK75
SK5/SK85, SK4/SK95,
SK3/SK105, SK2/SK120, SK2+Cr4, etc.
U.S. SAE-AISI specification
1050, 1060, 1065, 1070, 1075, 1080, 1086, 1090, 1095, etc.
EU W-Nr. specification
C55S/1.1204, C60S/1.1211, C67S/1.1231, C75S/1.1248,
C85S/1.1269, C90S/1.1217,
C100S/1.1274, C125S/1.1224, C125Cr2/1.2002.
Most common, often supplied specifications
Most often supplied grades are S50CM/SAE1050, S75CM/SAE1075,
SK85/SAE1086, SK95/SAE1095,
SK120(SK2/SK2+Cr4)/C125S.
ANNEALING, QUENCHING, TEMPERING
HEAT TREATMENT OF HIGH CARBON STEEL
High carbon steels can be heat treated to improved mechanical properties. Heat treatment includes annealing, normalizing, precipitation hardening, quenching, and tempering. Annealing soften steel, helps release internal stress, and makes the steel easier to be formed or cold-worked.
Quenching and tempering are most popular process of heat treatment for high carbon steels. Heat treatment requires continuous furnace, instead of batch furnace. Horizontal furnace is more popular than vertical one conducting heat treatment for high carbon steel.
Quenching and tempering are processes that strengthen and harden materials like steel and other iron-based alloys. The process of quenching or quench hardening involves heating the material and then rapidly cooling it to set the components into place as quickly as possible. The process is tightly controlled, with the heating temperature, cooling method, cooling substance and cooling speed all dependent upon the type of material being quenched and the desired hardness. Quenching and tempering consist of a two-stage heat-treatment process.
Stage one includes hardening, in which the steel is austenitized to approximately 900°C and then quickly cooled with water or oil, or liquid-lead, or else. Stage two consists of tempering the material to obtain the desired material properties. Quenching and tempering achieve a fine-grained and homogeneous microstructure. Quenched and tempered steel is characterized by high strength and good ductility.
HARDNESS OF HIGH CARBON STEEL
High caron steels may have different yield strength, tensile strength, and hardness value depending on their carbon contents, cold reduction ratio, and tempering conditions (heat treatment).
Annealed and skin-passed: HV180–HV220, or HRB92-95 or below.
Rolled hard: HV250-HV370
Quenched and tempered: HV480 – HV630, or HRC 50-63.
For example, after quenching and tempering, hardness of SK85/SAE1086 could be as high as HV670-720, or HRC 59-61.
Tensile strength of SK2Cr4 with quenched and tempered condition could be as high as 1,300MPa up to 2,100MPa,
High carbon steels are usually used for
Applications of High Carbon Steel
High carbon steels, due to relative high strength and hardness, are usually used for the following products.
measuring tape, razor blade, surgical blade, kitchen knife, box cutter, cutter knife, utility knife, coil spring, wood cutting tool, saw, shim stock, gasket, etc.