35CrMo Structural Steel Standards

I. 35CrMo Structural Steel Material Overview

 

35CrMo is a specification for an alloy structural steel (alloy quenched and tempered steel) widely used in engineering applications.

 

II. Chemical Composition of 35CrMo Structural Steel

 

It primarily contains carbon (C), silicon (Si), manganese (Mn), chromium (Cr), molybdenum (Mo), and nickel (Ni). The carbon (C) content is 0.32-0.40%, the silicon (Si) content is 0.40-0.70%, the manganese (Mn) content is 0.40-0.70%, the molybdenum (Mo) content is 0.15-0.25%, and the nickel (Ni) content is ≤0.30%.

 

 

III. Mechanical Properties

 

• Strength Characteristics

It exhibits high static strength, impact toughness, and a high fatigue limit. Its hardenability is higher than that of 40Cr, and it exhibits high creep strength and endurance strength at high temperatures. Its long-term operating temperature can reach 500°C. Its plasticity during cold deformation is moderate, and its weldability is poor. Even at temperatures as low as -110°C, it maintains high static strength, impact toughness, and fatigue strength. It also exhibits good hardenability, no tendency to overheat, minimal quenching deformation, acceptable ductility during cold deformation, and moderate machinability, but exhibits Type I temper brittleness.

• Comprehensive Mechanical Properties

After appropriate heat treatment (such as quenching and tempering), 35CrMo structural steel exhibits excellent comprehensive mechanical properties, meeting a wide range of engineering requirements.

 

IV. Compliant Standards

 

The applicable standard is GB/3077-1999, and it also complies with JIS G4053:2003.

 

V. Applications

 

• Mechanical Manufacturing

It is used to manufacture critical parts for various machines subject to impact, bending, torsion, and high loads, such as rolling mill herringbone gears, crankshafts, hammer rods, connecting rods, fasteners, steam turbine engine main shafts and axles, engine transmission parts, and large electric motor shafts.

• Energy Equipment

Used in the manufacture of key parts for energy equipment, such as oil drilling equipment, power station equipment, and wind turbines.

• Other Industries

It can be used to manufacture boiler bolts with operating temperatures below 400°C, nuts below 510°C, and high-pressure seamless thick-walled conduits for chemical machinery (temperatures between 450-500°C, non-corrosive media). It can also replace 40CrNi in the manufacture of high-load drive shafts, turbine engine rotors, large-section gears, and support shafts (with diameters less than 500mm). It can also be used in the manufacture of bridges, bearings, gears, tools, molds (such as cutting tools, punches, and extrusion dies), oil drill pipes and pipelines, and key components of nuclear equipment.

 

VI. Processing and Heat Treatment

 

Processing: 35CrMo structural steel has excellent machinability and can be formed and processed using a variety of processes.

Heat Treatment: Quenching and tempering are typically required to achieve the desired mechanical properties and microstructure. The specific heat treatment process should be determined based on the specific application requirements and steel specifications.