No. 35 No. 20 steel plate heat treatment and properties

The No. 35/20# steel plates are carbon structural steel plates that implement the GB/T 711 standard, generally referred to as high carbon steel.

There are various heat treatment processes for No. 35 steel plates and No. 20 steel plates, such as hot rolling, normalizing, annealing, tempering, quenching and tempering, etc. Generally, the finished products are made according to the requirements and then the heat treatment process is carried out to achieve the performance.

Chemical composition of No. 35 steel plate:
Carbon C of No. 35 steel plate: 0.32-0.40
Silicon Si of No. 35 steel plate: 0.17-0.37
No. 35 steel plate manganese Mn: 0.50-0.80
Sulfur S of No. 35 steel plate: ≤0.035
Phosphorus P of No. 35 steel plate: ≤0.035
No. 35 steel plate chromium Cr: ≤ 0.25
No. 35 steel plate nickel Ni: ≤0.25
No. 35 steel plate copper Cu: ≤0.25

Chemical composition of No. 20 steel plate:
No. 20 steel plate C 0.17-0.23,
No. 20 steel plate Si 0.17-0.37,
No. 20 steel plate Mn 0.35-0.65,
No. 20 steel plate P≤0.035,
No. 20 steel plate S≤0.035,
No. 20 steel plate Ni≤0.30,
No. 20 steel plate Cr≤0.15,
No. 20 steel plate Cu≤0.25.

Mechanical properties of No. 35 steel plate:
Tensile strength of No. 35 steel plate σb (MPa): ≥530(54)
No. 35 steel plate yield strength σs (MPa): ≥315(32)

Elongation of No. 35 steel plate δ5 (%): ≥20
No. 35 steel plate area shrinkage rate ψ (%): ≥ 45
Impact energy Akv (J) of No. 35 steel plate: ≥55
Impact toughness value of No. 35 steel plate αkv (J/cm2): ≥69(7)
No. 35 steel plate hardness: no heat treatment ≤ 197HB
Sample size of No. 35 steel plate: the sample size is 25mm[1]

No. 35 steel plates and No. 20 steel plates are widely used in construction machinery.