12Cr1MoV, alloy structural steel. Unified digital code: A31132. Standard: GB/T3077-1999

Description:

1. The two digits at the beginning of the steel grade indicate the carbon content of the steel, expressed in ten-thousandths of the average carbon content, such as 40Cr, 25Cr2MoVA alloy pipe

2. The main alloying elements in steel, except for individual microalloying elements, are generally expressed in percentage. When the average alloy content is <1.5%, generally only the element symbol is indicated in the steel grade without indicating the content, but in special cases where confusion is likely, the number "1" may also be marked after the element symbol. For example, steel grades "12CrMoV" and "12Cr1MoV", the former has a chromium content of 0.4-0.6%, and the latter 0.9-1.2%, with all other components identical.

3. Vanadium V, titanium Ti, aluminum Al, boron B, rare earth RE and other alloying elements in steel are all microalloying elements. Although their content is very low, they should still be indicated in the steel grade. For example, in 20MnVB steel, vanadium is 0.07-0.12%, and boron is 0.001-0.005%.

4. High-grade high-quality steel should have "A" added at the end of the steel grade to distinguish it from general high-quality steel.

5. For alloy structural steel with special purposes, the steel grade is prefixed (or suffixed) with a symbol representing the use of the steel. For example, 30CrMnSi steel specially used for rivets and screws is designated as ML30CrMnSi.

12Cr1MoV steel plate weight calculation formula: length × width × thickness × 0.00785 = kg/m

Chemical composition:

Mechanical properties:

Main characteristics:

   Compared with 12CrMoV steel, this steel has higher oxidation resistance and heat strength. The creep limit and endurance strength values of this steel are very close, and it has high plasticity under sustained tensile stress; the steel has good processability and weldability, but requires preheating to 300°C before welding and stress relief treatment after welding.

It is a steel grade widely used for superheaters, headers, and main steam pipes of high-pressure, ultra-high-pressure, and subcritical power station boilers. It still has high heat strength and oxidation resistance at 580°C, and high endurance plasticity. The production process is relatively simple, and the welding performance is good, but it is sensitive to normalizing cooling rate. Long-term use at 580°C will produce type II temper embrittlement caused by the segregation of impurity elements such as phosphorus at grain boundaries. Long-term use will also cause pearlite spheroidization.