Material Name: high quality carbon structural steel
Grade: 45Mn
● Features and application:
45Mn carbon quenched and tempered steel, strength, toughness and hardenability of steel is higher than 45, obtained after quenching the better mechanical properties, cutting performance is still good, but poor weldability, low cold plastic deformation, there tendency to temper brittleness, generally used in the quenched state, but also in the quenched and tempered or normalized state use. Manufacture of parts for wear and tear, such as shaft, spindle, crank, splined shaft, connecting rod, universal joint shaft, gear lever, gear, clutch plates, bolts, nuts and so on.

● Chemical Composition:

Carbon C: 0.42 ~ 0.50

Si Si: 0.17 ~ 0.37

Manganese Mn: 0.70 ~ 1.00

Sulfur S: ≤ 0.035

Phosphorus P: ≤ 0.035

Chromium Cr: ≤ 0.25

Ni-Ni: ≤ 0.25

Copper Cu: ≤ 0.25

● Mechanical Properties:

Tensile strength σb (MPa): ≥ 620 (63)

Yield strength σs (MPa): ≥ 375 (38)

Elongation δ5 (%): ≥ 15

Reduction of area ψ (%): ≥ 40

Impact energy Akv (J): ≥ 39

Impact toughness αkv (J/cm2): ≥ 49 (5)

Hardness: no heat treatment ≤ 241HB; annealed steel ≤ 217HB

Heat treatment: 850 ℃ normalizing, 840 ℃ quenching, 600 ℃ tempering.

● Main features:

This is an alternative to 40Cr steel, the more successful of the new steel, which has high strength, hardness, wear resistance and good toughness, its hardenability slightly higher than the 40Cr in the critical oil quenching diameter of 18 ~ 33mm; normalizing good after cutting, cold drawing, rolling, tapping, and forging, heat treatment process performance are good, high temperatures, grain growth, oxidation, decarburization orientation and deformation hardening tendencies are small; but have temper brittleness, tempering somewhat less stable than the 40Cr steel. [Application Example] This steel is generally used in the quenched state, temperature range -20 ~ 425 ℃, the main place of 40Cr steel production, a small section of the quenched parts, such as automotive axle, steering shaft, worm, spline axes and spindle, gear, etc. They can also replace the 40Cr steel production Φ250 ~ 320mm hoist a large section of the intermediate shaft and other parts. When the production of smaller parts can be replaced when the steel 40CrNi steel use.