30CrMo, also known as chromium-molybdenum alloy steel, is a medium-carbon quenched and tempered steel with high strength and toughness.
This steel exhibits excellent high-temperature strength below 500°C, along with good hardenability, tempering stability, and corrosion resistance. 30CrMo is widely used in the manufacture of parts requiring high strength and wear resistance, such as automotive engine crankshafts, planetary gears, and drive shafts. It is also used in the manufacture of industrial equipment such as high-pressure vessels, boilers, and petroleum machinery.
Chemical Composition
The main chemical composition of 30CrMo is: carbon 0.26%–0.34%, chromium 0.80%–1.10%, and molybdenum 0.15%–0.25%. Sulfur and phosphorus contents are both below 0.035% to ensure material purity. It also contains silicon 0.17%–0.37%, manganese 0.40%–0.70%, and nickel and copper no more than 0.030%. These ingredients contribute to 30CrMo’s excellent mechanical and processability. Physical Properties
Density: 30CrMo has a density of approximately 7.85 g/cm³.
Coefficient of Thermal Expansion: Between 20°C and 100°C, the average coefficient of thermal expansion is approximately 11 × 10^-6/°C.
Thermal Conductivity: Approximately 53 W/m·K at 20°C.
Specific Heat: Approximately 0.46 J/kg·K at 20°C.
Resistivity: Approximately 0.72 Ω·mm^2/m at 20°C.
Modulus of Elasticity: Approximately 200 GPa at 20°C.
Heat Treatment Schedule: The heat treatment schedule for 30CrMo is as follows:
Annealing: 650°C-700°C, hold at this temperature, then slow cooling to improve plasticity and toughness, making it suitable for cold working and welding.
Normalizing: 860°C-900°C, hold at this temperature, then air cool to increase hardness and strength while reducing toughness.
Quenching: 860°C-900°C, water or oil cooling, to form a martensitic structure and improve hardness and strength.
Tempering: 420°C-540°C, water or oil cooling, to improve the balance between hardness and toughness.
Product Specifications
30CrMo products include hot-rolled and cold-rolled plates, sections, and pipes. Plate thicknesses range from thin (3.0-25mm) to extra-thick (80-100mm), widths from 500mm to 3000mm, and lengths from 2000mm to 4000mm.
Application Overview
Due to its excellent mechanical properties and wide adaptability, 30CrMo is widely used in various fields:
Mechanical Manufacturing: Used in the manufacture of various mechanical parts subject to high forces and harsh operating environments, such as shafts, gears, bearings, and connecting rods.
Petrochemical Industry: Used in the manufacture of various pressure vessels, pipelines, storage tanks, and other equipment, as well as high-pressure pipes operating in nitrogen-hydrogen media at temperatures not exceeding 250°C.
Automotive Manufacturing: Used in key automotive components such as engine crankshafts, axles, and gears.
Shipbuilding: Used in the manufacture of various ship components such as hull structures, propellers, and rudders.
Of course, if you have 30CrMo forging needs, you can partner with Mulan Metal. Mulan Metal is a professional Chinese metal casting manufacturer that has helped clients in over 30 countries complete custom casting production and has received widespread recognition. We look forward to hearing from you.
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