Spring heat treatment equipment
Heat treatment equipment is an important basis for ensuring spring quality.
1. Resistance furnace Resistance furnace is one of the most commonly used equipment in general spring manufacturing plants. There are the following types of resistance furnaces.
a. Box furnace The medium temperature box furnace is widely used in spring production. The equipment is easy to operate and maintain, which can meet the general process requirements of heat treatment and heating. The disadvantage is that it is heated in the air medium, which is easy to produce an oxidation and decarburization layer on the surface of the spring. Important springs should not be heated in this type of furnace. The series specifications are shown in Table 1.
Table 1 Specifications and technical data of medium temperature box-type electric furnace series
The index when the furnace temperature is 850℃
Maximum working temperature
Effective size of furnace
mm mm mm
Start empty furnace heating time at 20℃
/(kg·h) Furnace bottom
Large load capacity
RX(RXQ) series RX-18-9133801950 300×650×250≤5≤260
Note: RXQ series furnaces are equipped with inlet pipes and outlet gas combustion pipes for introducing protective gas or dripping liquids such as kerosene.
Table 2 Specifications and technical data of well-type tempering resistance furnace
The index when the furnace temperature is 650℃
Highest number of jobs
/℃ Effective size of furnace
mm mm no-load loss
Empty furnace heating up
/h Max Health
RJ series RJ-35-63538031650 500×650≤6≤3210
RJJ series JJ-36-63680650500× 650≤6≤3280
b. Pit-type furnace Pit-type resistance furnace is mainly used for spring tempering, stress relief annealing and aging treatment. See Table 2 for series specifications.
c. Continuous hot blast tempering electric furnace The application of continuous hot blast tempering electric furnace has brought extremely significant comprehensive benefits to spring production. The electric furnace is more convenient to install and unload than pit type resistance furnaces and nitrate tempering furnaces, and it also has the characteristics of fast heating, uniform furnace temperature, high productivity and energy saving (compared with pit type resistance furnaces about 50% electricity). Therefore, the spring manufacturing industry has eliminated the long-used well-type resistance furnaces and nitrate tempering furnaces. The series specifications of continuous hot air tempering electric furnaces are shown in Table 3.
Table 3 Specifications and technical data of continuous hot air tempering furnace
Model Effective volume in furnace
mm mm mm Furnace body shape
mm mm mm inlet height
/mm Tempering temperature
/℃ When tempering
NO treatment material diameter
RJC-210200× 90×1000670×1200× 2000 500～60050～5005～60810.1～2.620300
RJC-310300× 90×1000770×1200× 2000 500～60050～5005～601210.1～3.230400
RJC-415400× 90×1500870×1200× 2800 500～60050～5005～602020.1～550700
RJC-420400× 90×2000870×1200× 3300 500～60050～5005～602620.5～6601000
RJC-630600×120× 30001120×1900× 510080050～50010～604831.0～101602000
2. Salt bath furnace The salt bath furnace is a heat treatment equipment heated by molten salt. Compared with the box furnace, it has the characteristics of fast heating, uniform temperature, and less oxidation and decarburization. Suitable for heat treatment of small diameter springs and important springs. There are two types of salt bath furnaces: internal heating type salt bath furnace and external heating type salt bath furnace. Salt bath furnaces can be divided into high temperature, medium temperature and low temperature according to the operating temperature. The high temperature is generally 900-1300℃, the medium temperature is 650-900C, and the low temperature is below 650C. Please check the relevant manuals or samples for the specifications and technical data of the salt bath furnace.
3. Protective atmosphere heating furnace, controlled atmosphere heat treatment furnace With the development of industry, the quality requirements of springs in production are getting higher and higher, and the heat treatment of springs does not allow excessive oxidation and decarburization on the surface. In conventional heat treatment, although the salt bath furnace heating can reduce the surface of the spring material or decarburize without oxidation. However, for various leaf springs with complex shapes made of strip steel, if they are heated in a salt bath furnace and quenched in oil, it is difficult to ensure the quality, and it is difficult to clean the spring after quenching, which will easily cause rust and reduce the spring. the quality of.
In recent years, the spring manufacturing industry has successively adopted controlled atmosphere heat treatment furnaces instead of traditional salt bath furnaces, and quenched and tempered valve springs, fuel injector pressure-regulating springs, motorcycle damping springs, planar scroll springs, and wave springs. deal with. The spring after heat treatment in a controlled atmosphere furnace has the advantages of bright surface, hardness, uniform metallographic structure, basically no decarburization and small deformation, which greatly improves the quality of the spring. In addition, after adopting a controlled atmosphere heat treatment furnace, there are benefits such as reducing labor intensity, saving energy, and reducing air pollution.
The specifications of the controlled atmosphere steel belt resistance furnace are shown in Table 4.
Table 4 Main technical parameters of RCG9 steel belt resistance furnace
Technical parameters RCG9-
30× 360× 5
Work area size
mm mm mm
Rated power/kW 50 807 690 120 150
Steel belt transmission speed
Gas consumption/(Nm ·h )2～33～44～5
Technical parameters RCG9-
Quenching tank volume/m48
Quenching 80 150 200 250 300
/(kg·h )Carburizing (carburized layer 0.1mm)
Furnace external size
mm mm mm
1600 × 8400
Upper size 1mm