Steel Material

Ordinary carbon steel only contains carbon as the main element in influence steel mechanical properties, in fact limited amount of manganese and silicon also exist in carbon steel plate and pipe products, and as the raw material contains elements of small quantities, such as nickel, chromium, aluminium, molybdenum and copper, and the bad impurities phosphorous and sulphur.

Mild Steel is mostly used for steel structural purpose, it is a special steel type which is not included in most steel standard. One significant difference is carbon content could reach up to 0.3%. Mild steel plate and pipe products show very good weldability and proper cold bending properties, it is always used in common projects.

Carbon steel contains higher level of manganese (1.0%-1.8%) is defined as Carbon Manganese steel. Manganese element can improve steel strength and toughness and hardening depth.

In the ordinary carbon steel based on the addition of an appropriate amount of one or more alloy elements and the composition of iron and carbon alloy. According to the different elements, and take appropriate processing technology, can get high strength, high toughness, wear resistance, corrosion resistance, low temperature, high temperature, non-magnetic and other special properties. Alloy steels contain element listed below in a quantity equal to or greater than the percentage.

Al 0.10%, B 0.008%, Bi 0.10%, Cr 0.30%, Co 0.10%, Cu 0.40%, Mn 1.65%, Mo 0.06%, Pb 0.40%, Se 0.10%, Si 0.50%, Te 0.10%, Ti 0.05%, W 0.10%, V 0.10%, Zr 0.05%, Lanthanides (each) 0.05%, other specified elements (except C, S, P, N) 0.05%.

Low alloy high strength steel, its alloy element content is low, the impurity content is relatively high, and generally it is used with no heat treatment. Alloy steel can be divided into low alloy steel (ω_M <= 5%), medium alloy steel (ω_M = 5% ~ 10%), high alloy steel (ω_M> 10%).

High alloy steel can be divided into alloy structural steel, alloy tool steel, it is featured with higher alloy content and lower impurity content, usually use heat treatment to improve steel strength and hardness.

Stainless steel is mainly used when high corrosion and oxidation resistance is required, alloy steel product developed with over 12% of chromium improved growth of chemical processing and power generating industries, including pressure vessel equipments, boilers, cylinders, etc. Stainless steel has developed into 3 common types: Austenitic, Martensitic, Ferritic, there are also special types: duplex, precipitation hardening and super alloys.

Austenitic steel is featured with high corrosion resistant for its high chromium and nickel content in stainless steel types, well known as iron-chromium-nickel steel which has fine mechanical properties(it can be hardened by cold-working) and no magnetic.

Martensitic steel contains only chromium element, no nickel, it is magnetic and can be hardened by heat treating. It is widely used for high hardness, strength and corrosion resistance requirements.

Ferritic steel is featured with high resistant to stress corronsion cracking, it is a kind of magnetic steel contained with only chromium and no nickel element, usually it is annealed to be cold worked an softened, while it can’t be hardened by heat treatment.