Wave spring vacuum heat treatment

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The wave spring is an important part installed on the high-pressure plunger spindle. It is connected to the end face seal structure of the spindle. The upper end is a V-shaped sealing ring and a V-shaped sealing ring, and the lower end is a graphite ring and a steel sleeve. Stressed state. Part size as shown.

Material grade: 60Si2MnA, GH3525-83; material thickness: 0.4mmn

Heat treatment technical requirements: ①440~510HV. ②The difference between the dimension F of each bump is not more than 0.1mm. ③The parts need to be subjected to 600 cycles of loading fatigue test. ④The height of the spring should be 3.700.4mm. ⑤ P=(18±20)N when the spring overwhelms the height of 2.35mm.

Parts processing process: blanking → supplementary annealing → punching ring wool → deburring and shaping → heat treatment → oxidation → inspection.

Selection of vacuum heat treatment parameters and prevention of thermal deformation

60Si2MnA steel is a high-quality spring steel with a wide range of uses. It has good hardenability, high strength and elastic limit after quenching and tempering, and also has high yield ratio, anti-relaxation ability and anti-tempering stability. . The disadvantage is that this kind of steel has a large tendency to decarburize, which has a direct impact on the strength and fatigue life of the parts. In addition, because the thickness of the spring sheet is very thin, only 0.4mm and the waveform is complex, it is difficult to meet the design requirements according to the conventional heat treatment specifications, and it is easy to deform.

The biggest advantage of using vacuum heat treatment; heat treatment deformation is small; improve the mechanical properties of the workpiece, prolong the service life; save energy; reduce pollution.

The vacuum heat treatment of the elastic element can avoid the unfavorable factors affecting the fatigue life of the spring, and the positive effect of vacuum degassing to improve the toughness of the material can improve the fatigue life and reliability of the spring.

In order to prevent decarburization, vacuum annealing and vacuum quenching + vacuum tempering are used from the annealing of raw material steel strips. 60Si2MnA spring steel contains Mn element with high vapor pressure. Therefore, the vacuum degree of Si-Mn spring steel is not easy to be too high during quenching and heating. 60Si2MnA spring steel has temper brittleness, so after vacuum tempering, it must be cooled by forced circulation in inert gas or oil cooling.

The purpose of vacuum non-oxidative heating is to avoid decarburization during heating. Air-cooled after the 440 ℃ heat preservation, the purpose is to avoid temper brittleness near Ms. In order to ensure that the radian of the parts after heat treatment is uniform and the arc height is within the required range, a quenching and tempering anti-deformation fixture is designed and manufactured.

Vacuum heat treatment results

Microstructure of parts after heat treatment The steel obtains a fine and uniform tempered martensite structure after final heat treatment.

Quality inspection of parts Measured hardness value: 460~464HV, qualified; measured value of size is qualified; rigidity inspection: 100% of the parts are within the range of P= (18±20)N and qualified.

Fatigue test According to the final inspection requirements of the parts, 600 fatigue tests are required. The test results show that after 600 fatigue tests, the technical indicators of the wave spring fully meet the design requirements, and the specimens and parts after the fatigue test are tested. No cracks were found in the magnetic inspection.

Through the manufacture of 60Si2MnA wave spring and the vacuum heat treatment process test, the complex part of the wave spring finally meets the technical indicators of the design requirements in terms of size and performance. After the installation test, it fully meets the design requirements. , and successfully passed the review of the parent organization.

Equipment selection: The VOGQ series vacuum heat treatment furnace produced by SIMUWU is a high-quality product for the vacuum heat treatment process of tooling and molds. Good temperature control accuracy and temperature control uniformity ensure the effective progress of the vacuum heat treatment process. SIMUWU specializes in the manufacture of vacuum furnaces, has more than ten years of relevant experience, and has a good reputation in the field of vacuum furnace manufacturing. The product line includes vacuum air quenching furnace, vacuum oil quenching furnace, vacuum brazing furnace, etc., which are widely sold in developed and developing countries.