Higher carbon steels

Carbon steels which can successfully undergo heat-treatment have a carbon
content in the range of 0.30–1.70% by weight. Trace impurities of various other
elements can have a significant effect on the quality of the resulting
steel.

Trace amounts of sulfur in particular make the steel red-short. Low alloy carbon steel, such as
A36 grade, contains about 0.05% sulfur and melts around 1426–1538 °C (2599–2800
°F). Manganese is often added to improve the hardenability of low carbon
steels.

These additions turn the material into a low alloy steel by some definitions,
but AISI‘s definition of carbon steel allows up to 1.65% manganese by
weight.

Medium-carbon ultrahigh-strength steels are structural steels with yield
strengths that can exceed 1380 MPa. Many of these steels are covered by SAE/AISI
designations or are proprietary compositions. Product forms include billet, bar,
rod, forgings, sheet, tubing, and welding wire.