30CrMoA alloy structural steel

30CrMoA alloy structural steel

30CrMoA alloy structural steel is a kind of carbon structural steel, which is mostly used in the manufacture of grand structures and construction projects, as well as to produce mechanical parts and components with greater strength and wear resistance. As one of the most commonly used alloy constructing steels in the market, 30CrMoA enjoys higher strength, toughness and good heat resistance, though it is quenched and tempered.

Chemical composition of 30CrMoA alloy structural steel

30CrMoA alloy structural steel is composed of major alloying elements including 0.27-0.33% carbon, 0.90-1.20% chromium, 0.17-0.37% molybdenum, 0.035% phosphorus, 0.035% sulfur, 0.15-0.30% silicon, 0.30-0.60% manganese, and the balance of iron, along with trace amounts of other elements. The microstructure is pearlite and, based on its chemical composition, 30CrMoA steel reaches maximum hardness of 320 HBW.

Applications of 30CrMoA alloy structural steel

30CrMoA alloy structural steel is mainly used for producing crankshafts, connecting rods, front/rear axles, and other automotive and aerospace components, as well as components of chemical process, petrochemical and power generating equipment. It is also used in military and firearm engineering. 30CrMoA steel is also employed in various types of mechanical parts, such as heavy-duty Bolts and Studs, shafts, keys, gears, spindles and pinions Gears and Sprockets.

Heat treatment of 30CrMoA alloy structural steel

30CrMoA alloy structural steel acquires its greatest hardness and best mechanical and wear-resistant properties after quenching treatment. It is usually quenched and tempered at a temperature between 845-900°C. Following quenching and tempering, it can be air cooled, or it can be cooled in spraying furnace. Moreover, 30CrMoA steel can undergo hardening, fillet cold-welding, normalizing, annealing and tempering.

Performance advantages of 30CrMoA alloy structural steel

With good physical and chemical properties as well as higher strength and wear resistant, 30CrMoA alloy structural steel is beneficial for other parts’ performance and stability. Its excellent wear resistance and strength make it resistant to abrasions. Additionally, 30CrMoA steel can be heat treated for additional strength and a longer service-life in various applications. Furthermore, it ages better than most other alloyed steels, which results in an overall better material performance.

Conclusion

30CrMoA alloy structural steel is one of the most frequently used alloy steels due to its superior strength, toughness and heat resistance. It is mainly used in automotive, aerospace, military and firearm engineering, and also in the manufacture of various mechanical parts and components. After proper heat treatment, 30CrMoA steel reaches maximum hardness of 320 HBW and benefits from its excellent wear resistance, good physical and chemical properties, and better aging performance.

30CrMoA alloy structural steel is a pearlite heat resistant steel, which has high strength and hardness, high temperature oxidation resistance, and good thermal fatigue resistance.

30CrMoA alloy structural steel is widely used to manufacture medium and high pressure boilers, high pressure steam pipes, compressed mechanical parts, all kinds of carburized parts and so on.

The chemical composition of 30CrMoA alloy structural steel is as follows: C: 0.27-0.34%, Si: 0.17-0.37%, Mn: 0.4-0.7%, Cr: 0.9-1.2%, Mo: 0.15-0.3%, P: ≤0.03%, S: ≤0.03%.

The mechanical properties of 30CrMoA alloy structural steel are as follows: Tensil Strength: 1030-1080MPa, Yield Strength: ≥910MPa, Elongation: ≥12%, Reduction Of Area: ≥45%.

30CrMoA alloy structural steel has good machinability and suitable for carburizing and nitriding, but its surface hardening response is not good.

When heated, 30CrMoA alloy structural steel should be preheated to 300℃-500℃ and then start quenching after uniform heating to 900℃-910℃; The quenching medium is oil or water, and it should be cooled quickly after quenching; Heavy load tempering should be carried out after quenching tempering. 30CrMoA alloy structural steel cannot be used in contact with sulfur-containing media.

In conclusion, 30CrMoA alloy structural steel has high strength and high temperature oxidation resistance, making it suitable for manufacturing medium and high pressure boilers and high pressure steam pipes. It has good machinability and is suitable for carburizing and nitriding, but its surface hardening response is not good.