The function of some groups of stainless steel Rolling mill?

This stainless steel Rolling mill group contains from 12% to 17% Cr. If the Cr content is at the lower limit (12 ~ 13%) then we have to control the carbon content C is not exceed 0.4% to avoid creating too much chromium carbide. Because Chromium Carbide depleted Cr content in the alloy background and reduce corrosion resitance. If the Cr content is up to 17%, the amount of C can be as high as 0.9 ~ 1.1% to increase the mechanical properties (stiffness) and still remain corrosion resistance.

The suitable temperature for heat treatment of this steels Rolling mill is: 950 ~ 1100 ° C. The coolling environment may be oil or air (due to of high content of % Cr so it should be easy to fabricate). The Ram temperatures depends on the specific requirements but must pay attention to avoid brittle ram type II in the temperature of 350 ~ 575 ° C (by quenching in oil. If stainless steel was cooled slowly will forms Cr23C6 steel brittle and reduce the corrosion resistance).

Martensite stainless steel Rolling mill has a high corrosion resistance in freshwater environments, because of the passive effect of chromium so that it is not corrode in acidic HNO3 (but corrosive in other acid). This stainless steels with low carbon content (eg: grade 403 and 410 of U.S) is used for stainless steel jewelry, stainless

Ferrite stainless steel Rolling mill has a higher elastic limit than Austenite stainless steel but the plastic deformation is lower, so, they are suitable for the normal fabrication (rolling, drawing, typing , stamping, etc.). Corrosion resistance of them depend on chromium content. In order to limit the local corrosion (point corrosion), we have to increase the chromium content above 20% and better increase more 2% of Mo alloy to be used in the marine enviroment, seawater and acid.

Ferrite Stainless Steel 410 304 Stainless Steel Rolling mill Composite

Depending on the Cr content, ferrite stainless steel be divided into three groups:

The stainless steel Rolling mill group 1 contains about 13% Cr, has very little of carbon (<0.08%). Add ~ 0.2% Al will prevent the forming of austenitic when ignition and facilitate for welding. Group of this stainless steel is widely used in the oil industry.
The stainless steel group 2 contains up to 17% of Cr is a Ferrite stainless steel group and it is most widely using because they can replace the austenite stainless steel in some allow conditions. This group is not contain Ni so it should be much cheaper. This stainless steel group is used widely in HNO3 acid production industry, the food processing, the architecture decoration ... The main disadvantage of this group is difficult to weld, when the temperature exceeds to 950 ° C, the area near the weld becomes brittle and be corroded at the connection (This problem can be overcome by lower % C or adding more content of Ti into stainless steel).
The stainless steel group 3 contains Cr from 20 ~ 30% Cr (ex: 446, 446B) have a very high antioxidant properties.

Rolling mill is a mill or factory where ingots of heated metal are passed between rollers to produce sheets or bars of a required cross section and form.

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