AISI 4140 Hardening Furnace

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AISI 4140 is defined as a low-alloy steel containing 1% Cr-Mo as a strengthening alloying element. Compared with AISI 4130, it has a higher carbon content, a good balance of strength, toughness, wear resistance, impact resistance and heat treatment ability, but it has poor weldability. AISI 4140 is generally supplied under quenched and tempered conditions, with a hardness of 28-32HRC.

1. Chemical Composition

Element	C	Si	Mn	P	S	Cr	Mo
Minimum	0.38	0.15	0.75	–	–	0.8	0.15
Max	0.43	0.35	1	0.035	0.04	1.1	0.25

2. Physical Properties

Density  g/cm3	7.85
Melting point  °C	1416
Poisson’s ratio	0.27-0.30
Machinability (AISI 1212 is 100% machinability)	65%
Coefficient of thermal expansion  μm/m°C	12.2
Thermal conductivity  W/(mK)	46
Modulus of elasticity  10^3 N/mm2	210
Resistivity   Ohm.mm2 /m	0.19
Specific heat capacity   J(kg.K)	460
Elastic modulus  10^3 N/mm2	100°C	200°C	300°C	400°C	500°C
	205	195	185	175	165
Thermal expansion  10^6 m/mK)	100°C	200°C	300°C	400°C	500°C
	11.1	12.1	12.9	13.5	13.9

3. Vacuum Oil Quenching

AISI 4140 heat treatment to obtain martensite structure after quenching should be carried out between 840°C and 875°C. Keep the steel for an appropriate time to fully heat the steel. The heat preservation time is 10-15 minutes for every 25mm section, and it should be tempered immediately after oil quenching.

4. Product Parameter

Model	Temperature Uniform Size(W*H*L)	MAX. Temperature	Ultimate Pressure	Temperature Uniformity	Loading Capacity
VOGQ-446-2	400*400*600mm	1300℃	4*10-1Pa/6.7*10-3Pa	±5℃	200Kg
VOGQ-557-2	500*500*700mm	1300℃	4*10-1Pa/6.7*10-3Pa	±5℃	300Kg
VOGQ-669-2	600*600*900mm	1300℃	4*10-1Pa/6.7*10-3Pa	±5℃	500Kg
VOGQ-7710-2	700*700*1000mm	1300℃	4*10-1Pa/6.7*10-3Pa	±5℃	700Kg
VOGQ-8812-2	800*800*1200mm	1300℃	4*10-1Pa/6.7*10-3Pa	±5℃	1000Kg
VOGQ-9915-2	900*900*1500mm	1300℃	4*10-1Pa/6.7*10-3Pa	±5℃	1200Kg
Remark: The working zone of equipment could be customized base on customer’s production.

Shanghai Geheng Vacuum Technology Co., Ltd. is a vacuum heat treatment furnace manufacturer with many years of experience in design, manufacturing and production. Mainly produce vacuum heat treatment furnace, vacuum sintering furnace, vacuum brazing furnace, New Energy And Environmental Protection Equipment and other vacuum equipments.Provide customized services, equipment work area can be based on customer output.