Chemical composition and mechanical properties of 20CrMnMo alloy steel plate

20CrMnMo is the grade of alloy structural steel. Unified digital code: A34202. The 20CrMnMo steel plate has good hot workability and good cutting performance after normalizing. However, the welding performance of this material steel plate is poor, so it should be properly preheated before welding and tempered in time after welding. 20CrMnMo alloy steel is commonly used in the manufacture of gears, camshaft connecting rods, etc.

Chemical composition of 20CrMnMo steel plate:
Carbon C: 0.17-0.23
Silicon Si: 0.17-0.37
Manganese Mn: 0.90-1.20
Sulfur S: allowable residual content ≤ 0.015
Phosphorus P: allowable residual content≤0.025
Chromium Cr: 1.10-1.40
Nickel Ni: allowable residual content ≤ 0.030
Copper Cu: allowable residual content ≤ 0.030
Molybdenum Mo: 0.20-0.30

Introduction to the mechanical properties of 20CrMnMo alloy steel plate:
Tensile strength (σb/MPa): ≧1180
Yield point (σs/MPa): ≧885
Elongation after break (δ5/%): ≧10
Area shrinkage (ψ/%): ≧45
Shock absorption energy (Aku2/J): ≧55
Brinell hardness (HBS100/3000) (annealed or tempered at high temperature): ≦217

Condition: With heat treatment (normalizing, annealing or high temperature tempering) or without heat treatment, the status should be indicated.

Heat treatment method of 20CrMnMo alloy steel plate:
Quenching heating temperature (℃): 850; Coolant: oil Tempering heating temperature (℃): 200; Coolant: water, air