Classification method of stainless steel forgings according to material
Dec. 03, 2020
There are many varieties of stainless steel, there are more than 140 kinds in the GB/T 20878-2007 standard, and there are about 200 kinds in actual life. Stainless steel forgings have different compositions, properties, and uses, and there are many classification methods. Generally speaking, they are classified according to the following methods.
Stainless steel forgings include stainless steel flanges and pipe fittings
(1) According to the main chemical composition elements. According to the main composition of steel or some special elements in steel, stainless steel forgings can be basically divided into: chromium stainless steel forgings (represented by Crl3), chromium-nickel stainless steel forgings (represented by Crl8Ni8 steel) Representative), chromium nickel molybdenum stainless steel forgings, chromium nickel manganese stainless steel forgings, high nitrogen stainless steel forgings and high molybdenum stainless steel forgings.
(2) Classification by organization This is the most traditional classification method. The metallographic structure of stainless steel forgings is closely related to its chemical composition and heat treatment state. According to whether the stainless steel forgings are heated to high temperature or cooled from high temperature to room temperature, there is no phase change and the main metallographic structure at room temperature to classify, there is Martensite Stainless steel forgings, austenitic stainless steel forgings, ferritic stainless steel forgings and austenitic-ferritic duplex stainless steel forgings.
(3) Classification by carbon content in stainless steel and other harmful impurity elements. Stainless steel forgings can be classified into ordinary stainless steel, low-carbon stainless steel, ultra-low-carbon stainless steel and high-purity stainless steel according to the carbon content and harmful impurity element content in steel.
(4) According to the classification of corrosion resistance, stainless steel can be divided into stress corrosion-resistant stainless steel forgings, pitting-resistant stainless steel forgings and corrosion-resistant stainless steel forgings.
(5) According to the classification of stainless steel use medium environment According to the use medium and environment, stainless steel can be divided into nitric acid resistant stainless steel, sulfuric acid resistant stainless steel, urea resistant stainless steel and seawater resistant stainless steel.
(6) Classification according to the main saving elements. Due to the preciousness and scarcity of certain elements, various countries have researched and produced some steels saved according to the main elements, such as nickel-saving stainless steel, nickel-free stainless steel and chromium-saving stainless steel, such as Cr- Mn-N and Cr-Mn-Ni-N stainless steel, and stainless steel with silicon and aluminum instead of chromium.
(7) Classification according to some characteristic constituent elements of stainless steel forgings According to some characteristic constituent elements, stainless steel forgings can be divided into high silicon stainless steel, high phase stainless steel forgings and high nitrogen stainless steel forgings.
(8) Classification according to the functional characteristics of stainless steel According to the functional characteristics of stainless steel, it can be divided into low-temperature and ultra-low temperature stainless steel forgings, non-magnetic stainless steel forgings, high-strength stainless steel forgings, superplastic stainless steel forgings, free-cutting stainless steel forgings, and heat-resistant stainless steel forgings.