What is the difference between 15CrMoR and Q345R steel plate

1. Chemical composition difference between 15CrMoR and Q345R steel plate:
15CrMoR steel plate chemical composition: C: 0.12-0.18, Si: 0.15-0.40, Mn: 0.40-0.70, P: ≤0.025, S: ≤0.010, Cr: 0.80-1.20, Mo: 0.30-0.60.

Chemical composition of Q345R steel plate: C: ≤0.20, Si: ≤0.55, Mn: 1.20-1.70, P: ≤0.025, S: ≤0.010, Cu: ≤0.30, Ni: ≤0.30, Cr: ≤0.30, Mo: ≤0.08.

The difference in mechanical properties between 15CrMoR and Q345R steel plate:
15CrMoR steel plate yield strength:
6-60mm: ≥295 MPa,
60-100mm: ≥275 MPa,
100-150mm: ≥255 MPa,
Tensile strength: 440-590 MPa.
Impact work: Temperature: 0℃: ≥31J.
Elongation: ≥19%.

Q345R steel plate mechanical properties:
yield strength: ≤16mm: ≥345 MPa,
16-36mm: ≥325 MPa,
36-60mm: ≥315 MPa,
60-100mm: ≥305 MPa,
100-150mm: ≥285 MPa,
150-200mm: ≥265 MPa.
Tensile strength: 470-640 MPa.
Impact work: Temperature: 0℃: ≥34J.
Elongation: ≥21%.

15CrMoR is steel for pressure vessels. 15CrMoR steel plate belongs to a kind of medium temperature hydrogen-resistant steel; Q345R steel plate is a boiler container plate, which is widely used in petroleum, chemical, power station, boiler and other industries. It is generally used to make reactors, heat exchangers, separators, gas pipes, and liquefied gas tanks, LPG cylinders, etc.