[ Types of stainless
steel ]
The martensitics steels are
leagues of iron and chromium (12 to 18%), with carbon content typically
above 0,10%. They have moderate resistance to corrosion; they become
harder by thermal treatment, and can reach elevated levels of mechanical
resistance and hardness; poor welding and they are magnetic. The types
of stainless steels are determined by the amount of each league element
that is added to the steel. The following league elements are added
to provide specific characteristics:
Cr (chrome) - The resistance to corrosion of the stainless steels
depends on the chromium content. As more chromium exists, higher is
the resistance to corrosion.
Ni (nickel) - It changes the crystallographic structure of the
league. It makes the steel more ductile. Small effect in the resistance
to corrosion. It makes the non magnetic steel.
C (carbon) - With only the chromium, the steel becomes harder
by temper through thermal treatment.
Ti (titanium) and Nb (niobium) - It avoids the combination of
the carbon with the chromium avoiding the resistance loss to the corrosion
and it improves the welding.
To choose the most appropriate steel to a specific application, it is
advisable an evaluation based on the following factors: corrosion; mechanical
properties; aesthetics; production; temperature; total cost to attend
different applications, several types of steel were developed.

