Thursday 11 June 2020

Types of stainless steel in machining: the most used

Stainless steel is one of the most widely used materials in the machining area, especially in flanges and p11 pipe. Although they are usually classified into up to five families, the types of stainless steel that represent almost all of its applications are two: austenitic and ferritic.

The different types of ss 321 plate are divided into degrees, and each of them has different properties in terms of its malleability, its hardness, its resistance to corrosion, etc.

Types of stainless steel
As we have advanced at the beginning, there are up to five main types of steel (although there is one of the families -that of precipitation hardening- that is usually included within three others). Also called families or categories, according to hastelloy c276 plate crystalline structure, that is, the solid form as their atoms, molecules, or ions are arranged and grouped.

310 Stainless Steel Plate

Austenitic: it has a nickel content of more than 7%, between 16 to 28% of chromium content, and very low carbon content. Which makes them very resistant to corrosion, having good malleability and weldability and excellent mechanical properties? EXAMPLE: ss 316 sheet

Ferritic: these ss 310 plate steels are basically chromium alloys within a range of 10.5% to 30%, but with very low carbon contents (0.08% in relation to martensitics), which makes them economical and with properties of reasonably good corrosion resistance and hardness.

 Martensitic: ss 304 sheet has high or low carbon content (up to 1.2%), 12% chromium and is built around type 410 iron. Its body-centered tetragonal martensite microstructure makes it hardenable by heat treatment (by cooling).

Austenitic and chrome moly pipe are the most used (they constitute 95% of stainless steelapplications), and that is why we dedicate the bulk of this post to them.

Austenitic stainless steel: the widest family
Austenitic is the type of stainless steel that represents two thirds of the production of this material since, since it contains chromium and nickel and very low carbon content. The ss 316l sheet IS mechanical as a great ductility in a wide range of temperatures (since it has the same microstructure even at cryogenic temperatures).

That means at the same time that it cannot be hardened by heat treatment. That is why ss 304L sheet is widely used in tube machining. Furthermore, it is easy to clean, which is especially important in other applications, in hygienic and sterile environments.

Austenitic p91 pipe stainless steel can be divided into three subgroups, the 100, 200 and 300 series .

Ferritic stainless steel
Ferritic stainless steels are simple chromium stainless steels, generally low carbon and nickel free, which makes them cheaper. The hastelloy c276 plate have reasonably good ductility and corrosion resistance, albeit less than austenitic ones, and like them they cannot be hardened by heat treatment as they have a ferrite microstructure like api 5l grade b (body centered cubic crystal) is present at all temperatures, due to the addition of chromium.

Ferritic stainless steel p22 pipe can be divided into various grades, of which the most common are 430, with 17% chrome, which is used in sinks, washing machine drums and dishwasher interiors, cutlery, refrigerator exteriors, etc.