20Mn2-alloy structural steel

Standard: GB / T 699-1999

[Main features]

With moderate intensity. Cold plastic deformation of high, good low temperature performance, welding and cutting may be acceptable. With the corresponding carbon content of steel compared to the high hardenability, quenching in oil, the critical diameter of 4 ~ 15 mm, but the heat treatment of overheating, decarburization sensitivity and tendency to temper brittleness.

[Application Examples]

Used to make the surface less demanding and the Ministry of the heart, cross-sectional size diameter <50mm carburizing parts, such as cars, tractors and machine tools manufacturing instead of 20Cr steel production carburizing small gears, small axes, low requirements of the piston pin, Cross pin head, diesel engine sleeve, valve plunger, gear lever, steel covers. In addition, hot-rolled and normalized steel in this state can also be used to make welding parts and screws, nuts and so on.

Chemical composition

[Chemical Composition] (%):

Carbon C: 0.17 ~ 0.24

Si Si: 0.17 ~ 0.37

Manganese Mn: 1.40 ~ 1.80

P P: "0.025

Sulfur S: "0.025

Chromium Cr: ≤ 0.30

Ni-Ni: ≤ 0.30

Copper Cu: ≤ 0.25

Mechanical properties

[Mechanical properties]

Tensile strength> = 785MPa

Yield strength> = 590MPa

Elongation> = 10%

Reduction of> = 40%

Impact absorbed energy> = 47Aku2 / J

     Hardness: ≤ 187HB