A high alloy steel against corrosion in air or chemical corrosion, stainless steel is a beautiful surface and corrosion resistant performance is good, do not have to go through surface treatment such as plating color, and play the stainless steel inherent surface properties, a used in many aspects of steel, often called stainless steel. Represents the properties of 13 steel, chromium nickel steel and high alloy steel 18-.

From the analysis of metallography, because stainless steel containing chromium and chromium film formed on the surface of thin film, the separated invasion and steel in oxygen corrosion effect.

In order to maintain the natural corrosion resistance of stainless steel, steel must contain at least 12% chromium.

Stainless steel type:

So according to the chemical composition and microstructure, to use gross classification.

With austenitic steel by class 18% Cr -8% Ni as the basic composition, the amount of each element were different,and the development of various uses of steel.

Classified according to chemical composition:

1. CR series: ferrite, martensite series

The CR-NI series: Austenitic precipitation hardening anomaly series, series, series.

In order to classify metallographic organization:

1. Austenitic stainless steel

The ferritic stainless steel

The martensite stainless steel

The double phase stainless steel.

The precipitation hardening stainless steel.