14Cr1MoR is a medium-carbon chromium-molybdenum alloy steel belonging to the pearlitic heat-resistant steel family. It is specifically designed for welded pressure vessels operating under high-temperature and high-pressure conditions, offering excellent elevated-temperature strength, resistance to hydrogen attack, and good weldability.
The grade designation has a clear technical meaning:
"14" indicates an average carbon content of approximately 0.14% (by weight), providing sufficient strength while maintaining good toughness and weldability;
"Cr1" means the chromium content is approximately 1% (by weight), which significantly enhances oxidation resistance, corrosion resistance, and high-temperature stability;
"Mo" refers to molybdenum content in the range of 0.50%–0.80%, a key element that improves high-temperature strength and resistance to temper embrittlement, effectively enhancing the steel’s creep strength above 450°C;
"R" is the first letter of the Chinese pinyin "Rong" (meaning "vessel"), indicating its application in pressure equipment.
Therefore, 14Cr1MoR denotes a specialized chromium-molybdenum heat-resistant steel for pressure vessels with ~0.14% carbon, ~1% chromium, and ~0.6% molybdenum.
This steel plate is widely used in high-temperature pressure equipment in industries such as petrochemicals, coal chemicals, fertilizers, and oil refining, including hydroprocessing reactors, heat exchangers, steam generators, pyrolysis furnace headers, and high-temperature separators. Its typical service temperature ranges from -20°C to 550°C, making it particularly suitable for components subjected to prolonged exposure to high temperature, high pressure, and hydrogen environments. Key features of 14Cr1MoR include: yield strength ≥295 MPa, tensile strength 450–590 MPa, and excellent overall mechanical properties; good microstructural stability and creep resistance at elevated temperatures; enhanced resistance to hydrogen attack and high-temperature oxidation due to the synergistic effect of chromium and molybdenum; and good weldability achieved through controlled carbon equivalent and heat treatment (typically normalized and tempered), ensuring reliable performance after welding and post-weld heat treatment (PWHT), minimizing risks of cracking and temper embrittlement.
Currently, 14Cr1MoR is manufactured and inspected in accordance with the Chinese national standard GB/T 713-2014 Steel Plates for Boilers and Pressure Vessels. Published and implemented in 2014, this standard replaced the previous GB 713-2008 edition and introduced more comprehensive and stringent requirements on chemical composition, mechanical properties, impact toughness, ultrasonic testing, and thickness-direction properties. It is one of the core standards widely adopted in China’s boiler and pressure vessel industry. As a key material for domestic mid-temperature, high-pressure, and hydrogen-exposed equipment, 14Cr1MoR has achieved large-scale production and engineering application, widely used in various hydrotreating units, and plays a vital role in supporting the localization and safe operation of China’s energy and chemical processing equipment.
Ultrasonic Testing (UT)
A key non-destructive testing technique that uses high-frequency sound waves to detect internal flaws in steel plates. The probe emits sound waves, which reflect when encountering defects such as cracks or inclusions. The receiver captures the echoes, enabling precise determination of defect location and size. With high sensitivity, strong penetration, and fast inspection speed, UT effectively ensures internal quality, widely used in the production of heavy plates, pressure vessel plates, and other high-end products to guarantee safety and reliability.
Magnetic Particle Testing (MT)
A common surface inspection method that magnetizes the workpiece, causing leakage magnetic fields at surface or near-surface defects like cracks or inclusions, which attract magnetic particles to form visible indications. Simple to operate and highly sensitive, MT is suitable for rapid inspection of surface and near-surface flaws in ferromagnetic materials, widely used for online or offline inspection of plate edges, ends, and welds, ensuring product quality and safety.
Penetrant Testing (PT)
A non-destructive method for detecting surface-breaking flaws. A penetrant liquid is applied to the cleaned steel surface, allowing it to seep into defects such as cracks or pores. After removing excess penetrant, a developer is applied, causing the trapped penetrant to bleed out and form visible indications. Simple and cost-effective, PT is suitable for inspecting surface defects in various non-porous materials, commonly used for welds, castings, and complex components, effectively ensuring surface quality of steel plates.
