What materials can be tempered in a box type tempering furnace?

Box type tempering furnace is a widely used equipment for heat treatment of metal materials. Its core function is to control the heating temperature and time, adjust the internal structure of the material, and optimize the mechanical and physical properties of the material.

1. Main application areas
Tool and mold manufacturing
Materials: High speed steel (W18Cr4V), cold work die steel (Cr12MoV)
Process: Temper at 560 ℃ -580 ℃ to reduce hardness to HRC 60-62, improve toughness, and reduce the risk of blade breakage.
Spring and fastener production
Material: 60Si2Mn spring steel, 35CrMoA bolt steel
Process: Tempering at 450 ℃ -500 ℃ to eliminate quenching stress, improve elastic limit and fatigue life.
Aerospace components
Materials: TC4 titanium alloy, Inconel 718 high-temperature alloy
Process: Tempering at 700 ℃ -800 ℃, optimizing the microstructure, improving high-temperature strength and creep resistance.
Precision Machinery Parts
Material: 45 # steel, 40Cr steel
Process: Temper at 520 ℃ -560 ℃ to reduce hardness to HRC 28-32, improve machinability and dimensional stability.

2. Key points of selection and process control
temperature control accuracy
Requirement: ± 1 ℃ (precision parts) to ± 5 ℃ (ordinary parts)
Technology: Adopting PID intelligent temperature controller and multi-point temperature measurement system to ensure temperature uniformity in the furnace ≤ ± 5 ℃.
Atmosphere protection function
Requirement: Easily oxidizable materials (such as titanium alloys and stainless steel) require nitrogen/argon protection
Design: Equipped with gas flow meter and double-layer sealed furnace door, with a leakage rate of ≤ 0.5%.
Heating rate and holding time
Parameters: Heating rate ≤ 10 ℃/min, insulation time according to material thickness (1-3h/cm)
Case: Tempering 45 # steel (560 ℃ × 2h) can significantly reduce residual stress.
Cooling method selection
Air cooling: suitable for low carbon steel and alloy steel
Oil/water cooling: suitable for high hardness tool steel (cooling rate needs to be controlled to prevent cracking)

3. Technical Cases and Data Support
Spring steel tempering case
Material: 60Si2Mn spring steel (quenched hardness HRC 58)
Process: 480 ℃ × 2h tempering
Effect: Hardness reduced to HRC 48, elastic limit increased by 15%, fatigue life extended by 3 times.
Aluminum alloy aging treatment case
Material: 7075 aluminum alloy (T6 state)
Process: 120 ℃ × 24h aging
Effect: The tensile strength has been increased to 600MPa, and the elongation rate has remained stable at over 8%.
Stainless steel tempering case
Material: 316L austenitic stainless steel
Process: 750 ℃ x 1h tempering
Effect: Corrosion resistance (salt spray test) improved by 40%, and high temperature strength (500 ℃) retention rate ≥ 90%.

4. Summary and Suggestions
Material adaptability: The box type tempering furnace is suitable for carbon steel, alloy steel, stainless steel, aluminum alloy, copper alloy, cast iron, titanium alloy, and powder metallurgy materials.
Process core: By precisely controlling temperature, time, and atmosphere, optimizing material structure, and improving mechanical properties and stability.
Selection suggestion:
Laboratory: Choose small equipment with high temperature control accuracy and good temperature uniformity (such as a 500 ℃ x 500mm furnace).
Industrial production: Prioritize the use of high-capacity and highly automated equipment (such as double-layer furnaces and program-controlled temperature control).

Through scientific selection and process optimization, the box type tempering furnace can significantly improve material properties and reduce production costs, making it an indispensable core equipment in the field of metal material heat treatment.