1. Basic Definition and Core Characteristics
12Cr1MoVG is a chromium-molybdenum-vanadium alloy boiler tube specified in the GB/T 5310 standard. It is a high-temperature heat-resistant steel. Its naming convention is as follows:
"12": Carbon content 0.08-0.15% (low-carbon design optimizes weldability);
"Cr1": Chromium content 0.90-1.20% (improves oxidation resistance);
"Mo": Molybdenum content 0.25-0.35% (enhances high-temperature strength);
"V": Vanadium content 0.15-0.30% (refines grain size and inhibits carbide aggregation);
"G": Boiler-specific designation.
Implementation Standard: Phosphorus ≤ 0.025%, sulfur ≤ 0.015%, and a 580°C high-temperature endurance strength report must be provided. 2. Core Performance Advantages
Heat Resistance: Long-term service temperature ≤ 565°C, short-term service temperature up to 580°C;
Creep Resistance: Endurance strength ≥ 75 MPa at 580°C (design life 100,000 hours);
Oxidation Resistance: Chrome and vanadium synergistic effect, steam corrosion rate < 0.05 mm/year;
Processability: Welding requires preheating to 200-250°C, and post-weld tempering at 700-740°C is mandatory.
3. Typical Applications
Power Industry: High-temperature superheaters and headers for subcritical/supercritical boilers;
Petrochemical Industry: Reactor piping for catalytic cracking units;
Special Applications: Pressure-bearing components subjected to cyclic thermal fatigue (e.g., turbine air ducts). 4. Comparison with Similar Materials
vs. 15CrMoG: The addition of vanadium increases the high-temperature strength of 12Cr1MoVG by 15%, but the cost is 8-10% higher;
vs. T22 (10CrMo910): Stronger steam corrosion resistance and shorter domestic procurement cycle;
vs. 12Cr2MoG: Lower molybdenum content, approximately 30°C lower operating temperature, but more cost-effective.
5. Procurement and Acceptance Key Points
Key Certificates: Material certificate including grain size (≥ Grade 5) and impact energy (AKV ≥ 40J) testing is required;
Testing Requirements:
100% ultrasonic testing (in accordance with GB/T 5777);
10% eddy current testing (for internal wall defect screening);
