Rolled Steel Products

Stainless Steel Flat Rolled Coil

Rolled Steel Products offers the following types of Stainless Steel Flat Rolled Coil

Austenitic stainless steels contain chromium and nickel (300 Series types) as well as chromium, nickel and manganese (200 Series types). Most stainless slit coils can be hardened by cold-working but not by heat treatment. All are non-magnetic in the annealed condition as well, though some may become slightly magnetic by cold-working. Stainless steel slit coils also have excellent corrosion resistance and unusually good formability. The stainless slit coils increase in strength as a result of cold work. With a nominal composition of 18% chromium and 8% nickel, Type 304 (sometimes referred to as 18-8 stainless) is the most widely used alloy in this group.

Ferritic stainless slit coils are straight-chromium 400 Series types that cannot be hardened by heat treatment and only moderately hardened by cold-working. They are magnetic with good ductility and resistant to corrosion and oxidation. Type 430 is the general-purpose stainless steel of this group. Type 430 is by far the most popular of all straight chromium stainless steels. It is the general purpose alloy of the ferritic class. This type contains approximately 17 percent chromium and is often referred as 17 chrome stainless. The higher chromium content imparts improved resistance of Type 430 is slightly less than carbon steel, but its thermal conductivity is one half that of carbon steel.

Martensitic stainless slit coils are straight-chromium 400 Series types that can be hardened by heat treatment. They are magnetic and, in mild environments, resistant to corrosion. They have fairly good ductility, and some can be heat-treated to tensile strengths exceeding 200,000 psi (1379 MPa). Type 410 is the general-purpose alloy of this group.

Properties of Stainless Steel
High oxidation-resistance in air at ambient temperature is normally achieved with additions of a minimum of 13% (by weight) chromium, and up to 26% is used for harsh environments. The chromium forms a passivation layer of chromium(III) oxide (Cr₂O₃) when exposed to oxygen. The layer is too thin to be visible, and the metal remains lustrous. The layer is impervious to water and air, protecting the metal beneath. Also, this layer quickly reforms when the surface is scratched. This phenomenon is called passivation and is seen in other metals, such as aluminum and titanium. Corrosion-resistance can be adversely affected if the component is used in a non-oxygenated environment, a typical example being underwater keel bolts buried in timber.

When stainless steel parts such as nuts and bolts are forced together, the oxide layer can be scraped off, causing the parts to weld together. When disassembled, the welded material may be torn and pitted, an effect known as galling. This destructive galling can be best avoided by the use of dissimilar materials for the parts forced together, for example bronze and stainless steel, or even different types of stainless steels (martensitic against austenitic), when metal-to-metal wear is a concern, but two different alloys electrically linked in humid environment work as pile and corrode faster. Nitronic alloys reduce the tendency to gall through selective alloying with manganese and nitrogen. Additionally, threaded joints may be lubricated to prevent galling.

Similarly to steel, stainless steel is not a very good conductor of electricity, with about a few percent of the electrical conductivity of copper.

Ferritic and Martensitic stainless steels are magnetic. Austenitic stainless steels are non-magnetic.