Accreditation Administration System:
In accordance with international standards, to distinguish between non_alloy and alloy steel two categories,
non_alloy steel, carbon steel is often called one of the major steel categories, in addition to iron and carbon
steel, it also contains small amounts of alloying elements into the charge Mn, Si, Al, impurity elements P, S
and gas N, H, O and so on. Steel is aiming for some kind of physical, chemical, or mechanical properties
and who wish to add a certain amount of alloying elements Cr, Ni, Mo, V, etc., and to control impurities
and harmful elements of another type of steel.
Divided into low_alloy steel, alloy steel, alloy steel and high alloy steel in the name suggests, to contain the
amount of alloying elements to be distinguished, in general, less than 3% of the total as low_alloy steel, 5%
~ 10% in alloy steel, high alloy steel is greater than 10%. According to GB / T 133_91 provides for non_
alloy steel and low alloy steel, alloy steel content of alloying elements should be within a certain threshold
value. In addition, with the development of metallurgical technology and progress, especially for the
definition and content of low alloy steel has changed a lot. For example, imported microalloying, controlled
rolling and cooling technology, as well as an extension of TMCP and other technology, the addition of alloying
elements in the traditional heat-treated steel and TMCP steels have significant differences.
