Introduction

Stainless steels contain typically 10-30 % chromium besides other elements like C, Mn, Si, S etc. Chromium imparts corrosion resistance to steel. Varying amounts of other alloying elements like Ni, Mo,
V, Ti, Ni, etc may be added to obtain certain specific property. There are different types of stainless steels like

Austenitic stainless steels: which contain 18% Cr, 8% Ni, and C is in between 0.03-0.15%

Ferritic stainless steels: which contain 12% to 30% Cr and 0.08% to 0.12%C.

Martensitic stainless steels: which contain around 13% Cr and C varying in between 0.15% to                                                     0.25%. Certain grades contain C 0.6% to 0.95%.

Duplex stainless steels: in which Cr is around 25%.

Precipitation hardenable stainless steel: contain 18-20% Cr, 8 to 10 % Ni and copper, Titanium,                                                                          Aluminum.

It may be noted that all stainless steels contain chromium and carbon besides other elements. Production of stainless steels requires controlling chromium and carbon.