35CrMo is the specification number of alloy structural steel, where "35" means that the carbon content is about 35%, and "Cr" and "Mo" represent the two alloying elements of chromium and molybdenum respectively. This steel has very high static strength, impact toughness and fatigue limit. Its hardenability is higher than 40Cr steel. It is also resistant to high temperatures, with long-term working temperatures up to 500°C.
From the chemical composition point of view, the main element content of 35CrMo is roughly: carbon (C) 0.32~0.40%, silicon (Si) 0.17~0.37%, manganese (Mn) 0.40~0.70%, phosphorus (P) ≤ 0.035%, sulfur (S) ≤ 0.035%, chromium (Cr) 0.80~1.10%, molybdenum (Mo) 0.15~0.25%. The precise ratio of these elements gives 35CrMo excellent mechanical and chemical properties.
Delivery status of 35CrMo steel: 35CrMo steel can be delivered in a heat-treated state (normalizing, annealing or high-temperature tempering) or in a non-heat-treated state. The specific delivery status should be noted in the contract to ensure that the customer's needs and usage requirements are met.
According to the carbon equivalent calculation formula recommended by the International Institute of Welding (IIW): Ceq=C+1/6Mn+1/5(Cr+Mo+V)+1/15(Ni+Cu)(%).First,when Ceq<0.40%, the hardening tendency of the steel is not obvious and the weldability is excellent. No preheating is required during welding and can be welded directly.Secondly, when Ceq=0.40~0.60%, the hardening tendency of the steel gradually becomes obvious, and the weldability is acceptable. When welding, proper preheating before welding and slow cooling after welding should be adopted to control the energy of the weld seam. Finally, when Ceq>0.60%, the steel has a strong hardening tendency and poor weldability. It is a type of steel that is difficult to weld, and high preheating temperatures and strict process measures must be taken to select appropriate welding materials.
As an alloy structural steel, 35CrMo has a series of remarkable properties that make it widely used in various industrial applications.
First, 35CrMo exhibits extremely high strength and hardness. After proper heat treatment, its tensile strength and yield strength can reach very high levels and can withstand large pressure and bending stresses. This makes it excellent when manufacturing parts and structures that need to withstand high loads.
Secondly, 35CrMo has excellent welding performance and processing performance. It can be connected by common welding methods, and at the same time can show good performance during processing, such as cutting, bending, curling, etc. However, it should be noted that preheating may be required before welding to ensure the quality and mechanical properties of the welded joint.
In addition, 35CrMo also has good heat resistance and corrosion resistance. It can maintain stable structural performance in high-temperature environments and is suitable for high-temperature equipment and pipelines. At the same time, it can also resist corrosion by some weak acids, weak alkali and other chemical substances, and has a long service life.
In addition to the above characteristics, 35CrMo also has excellent toughness and can maintain stable performance under shock and vibration environments. This gives it a unique advantage when manufacturing parts that require impact and impact resistance.
35CrMo is widely used and is favored for its excellent mechanical properties and heat treatment properties. The main application areas of 35CrMo steel are as follows: Machinery manufacturing: 35CrMo steel is widely used in the manufacture of key parts that withstand impact, bending torsion and high loads in various machinery, such as herringbone gears, crankshafts, hammer rods, connecting rods, and fasteners . It is also commonly used in components in engines and transmission systems, such as engine main shafts, transmission components, and large motor shafts.Petrochemical industry: In petroleum machinery, 35CrMo steel is used to make punches, as well as bolts for boilers with operating temperatures below 400 degrees Celsius and nuts below 510 degrees Celsius. In addition, it is also used in chemical machinery to manufacture high-pressure seamless thick-walled pipes, especially suitable for environments with temperatures of 450 to 500 degrees Celsius and non-corrosive media.Power and energy: 35CrMo steel plays an important role in turbine generators, used to manufacture rotors, main shafts and heavy-duty drive shafts. Its high temperature creep strength and durable strength make it ideal for high temperature service environments.Automobile and transportation: In the vehicle manufacturing industry, 35CrMo steel is used to manufacture transmission components and other key structural parts. Its high strength and excellent toughness can meet the requirements of high-load working environments.Fastener industry: 35CrMo steel is also commonly used to manufacture fasteners, such as hexagonal bolts, hexagonal nuts, stud bolts and fully threaded studs. These fasteners are widely used in chemical plants, high-pressure pipelines, oil pipelines, high-temperature blast furnaces and other environments due to their high strength and excellent corrosion resistance.
Although 35CrMo steel has a wide range of applications, factors such as the working environment, load conditions, and material requirements need to be comprehensively considered in specific applications to ensure that the most appropriate material is selected. In addition, correct heat treatment processes and processing methods are also crucial to ensure the performance of 35CrMo steel and extend its service life.
