Introduction and classification of Crl3 stainless steel

Stainless steel materials are classified in many ways: austenite, martensite, ferrite and two-phase structure; There are two kinds of stainless steels: chromium and chromium nickel; According to the use function, it can be divided into high-strength type, low-temperature type, free cutting type, non-magnetic type and so on.

Excellent mechanical properties, corrosion resistance and high cost performance are the advantages of martensitic stainless steel, so it is widely used in manufacturing parts. Its performance can change with temperature. It is often used in temperature sensitive environments, such as steam impeller, gas valve, pressure vessel Offshore oil exploitation platform, etc. In terms of element content of martensitic stainless steel, generally, the Cr content is between 12wt.% – 18wt.%, and the C content is usually greater than 0.1%, because its structure is martensitic phase after quenching and strengthening, which makes the steel “self hardening”.

As a typical martensitic stainless steel, 2Crl3 has a good balance between mechanical properties and production cost, so it has high cost performance and wide application environment. According to GB / t20878-2007 and similar national steel standards.

20crl3 is 2Crl3, which is a new brand expression, but we are still used to calling it 2Crl3. The chromium content of Crl3 steel is basically the same. In order to meet the corrosion resistance of this group of steel, the Cr content is specified to be 11.5-14%, The corrosion resistance of Crl3 series is different due to the difference of carbon content, but they are all in a horizontal range.

Type 2 & 13 stainless steel belongs to the type with low carbon content in Crl3, which has a good balance between strength and initial property. It is used for many corrosion-resistant structural parts. 3ch3 and 4Crl3 section steels are mostly used for wear-resistant parts due to the high C content. Under the heat treatment process, 2Crl3 can realize the phase change of heating and cooling by virtue of the stable austenite of element C. the eutectoid austenite and austenitization of ferrite make ay transform each other, and PM transform under the critical cooling rate. Under the action of element Cr, the critical cooling rate does not need to be very high, Even if air cooling will produce martensite phase, rapid cooling should be adopted in order to obtain a large amount of martensite. These characteristics make 2Crl3 have better microstructure and mechanical properties after heat treatment.

It is worth noting that the carbon content of this group of steels is different, resulting in some differences in the structure produced by cooling after austenitizing. Generally speaking, they are all martensitic stainless steel, but if the carbon content is low, for example, 0crl3 is martensite and ferrite after austenitizing and cooling, because the carbon in phase a cannot be completely saturated, The structure of 4Crl3 with high carbon content is martensite and carbide. Because the austenitizing temperature can not completely dissolve the carbide, there is a certain residue, while 2Crl3 is an orthodox martensitic stainless steel.