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What is the material of pipeline 12Cr5Mo, and how is it pronounced? Please tell me, extra points for experts
I’m not an expert, but I’ll try to share my thoughts as a starting point for further discussion: The new grade of 12Cr5Mo alloy pipe corresponds to the national standard material 12Cr5Mo. This is a martensitic stainless steel, equivalent to the older grade 1Cr5Mo. The chemical composition is as follows: Carbon C: ≤0.15; Silicon Si: ≤0.50; Manganese Mn: ≤0.60; Sulfur S: ≤0.030; Phosphorus P: ≤0.040; Chromium Cr: 4.00–6.00; Molybdenum Mo: 0.40–0.60; Nickel Ni: ≤0.60. The mechanical properties of 12Cr5Mo are as follows: Tensile strength σb (MPa): ≥590; Strength at 0.2% strain σ0.2 (MPa): ≥390; Elongation after fracture δ5 (%): ≥18; Hardness: ≤200HBW
It is a Maraging-type stainless steel 12Cr5Mo alloy tube, which represents a new grade in China.
12Cr5Mo material (requires normalizing + tempering heat treatment process) 1: Scope of application Suitable for hot-formed alloy steel pipe fittings. 2: Process specifications Heat treatment process: Normalizing + tempering. Temperature: Normalizing temperature – 900°C to 940°C; Tempering temperature – 700°C to 730°C. Holding time: 3 minutes per 1 mm, with a minimum of 120 minutes. Cooling method: The furnace is cooled slowly to 400°C, followed by air cooling.
We all call it 12luo (fourth tone) 5mu (fourth tone)
This grade contains 5% chromium; it does not qualify as a martensitic stainless steel, but rather is an alloy steel. Stainless steel is considered to be such only when its chromium content is greater than 13 percent
Cr5Mo is a pearlitic heat-resistant steel, and it is typically supplied in the normalized and tempered condition
The last edit to this post was made by tjhxtgg on 2017-12-7 at 22:30. According to the GB/T 9948-2013 standard, the correct way to read 12Cr5Mo is: 12 chromium 5 molybdenum； 1Cr5Mo was modified to 12Cr5MoI and 12Cr5MoNT ； I represents isothermal annealing, NT represents normalizing + tempering ；