45Mn2 alloy steel pipe

45Mn2, alloy structural steel.
Standard: GB/T 3077-1999

45Mn2 alloy steel pipe is a medium-carbon quenched and tempered steel with high strength, wear resistance and hardenability. The critical hardening diameter in oil is 10-25 mm, and the critical hardening diameter in water is 22-45 mm.

45Mn2 alloy steel pipe has good comprehensive mechanical properties after quenching and tempering, and the machinability is still good; but it has the disadvantages of overheating sensitivity and tempering brittleness during heat treatment, easy cracking in water quenching, sensitivity to white spots, low weldability and cold deformation plasticity, etc. .

45Mn2 chemical composition (%):

C	Si	Mn	S	P	Cr	Ni	Cu
0.42～0.49	0.17～0.37	1.40～1.80	≤0.035	≤0.035	≤0.030	≤0.030	≤0.030

45Mn2 Mechanical properties:

Tensile strength (σb/MPa)	Yield point (σs/MPa)	Elongation after break (δ5/%)	Reduction of area (ψ/%)	Impact absorption energy (Aku2/J)	Brinell hardness (HBS100/3000)
≥885	≥735	≥10	≥45	≥47	≤217

45Mn2 alloy steel pipe heat treatment:
Heating temperature for the first quenching (℃): 840; coolant: oil
Second quenching heating temperature (°C):-
Tempering heating temperature (°C): 550; Coolant: water, oil

After 45Mn2 alloy steel is quenched and tempered at high temperature, it can obtain high strength and good toughness with good coordination, that is, it has good comprehensive mechanical properties. It is often used in the manufacture of shafts, connecting rods, tight firmware etc.

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