The dish spring deformation energy per unit volume is large, for shock absorption and dissipation of energy, under the long-term impact, resulting in radial crack; disc spring in spring when the concave inner surface and the end bearing at the junction, the maximum tensile stress, the failure analysis of disc spring:
1 due to the material composition is unreasonable, the composition segregation leads to disc spring performance is not uniform, for example, 60Si2Mn is used as the disc spring material, low content of Si, reduce the disk spring yield strength, resulting in embrittlement of parts occur in advance, and even cracking; P content was high, has exacerbated the brittle tendency of steel and component segregation and debris; the existence of segmentation of the continuity of the matrix crack, become sensitive, especially when the distribution in the surface of parts, easy to cause the stress concentration, stress crack corrosion preferred channel.
2 machining cracks. Disc spring processing by hot forging, quenching and high temperature tempering quenching and tempering treatment, shot peening, disc spring of internal micro cracks will appear in the whole process, resulting in stress concentration, in use process, if the load will accelerate the disc spring fatigue failure and crack.
3 stress corrosion. Disc spring when the tensile stress when the load is removed, the disc spring, the remained residual tensile stress of disc spring, if the long-term work in the acidic liquid or high humidity environment, in under the action of tensile stress in the solution of hydrogen aggregation, adsorbed on the surface of the hole, corrosion and other defects. The surface energy of atoms, or strong binding force reduction, the local stress concentration increases, when the crack nucleation energy is greater than the stress intensity factor at the crack tip, which leads to brittle fracture of crack nucleation and propagation environment, micro cracks appear, lead to premature fatigue failure of disc spring.
4 heat treatment is not reasonable. Disc spring heat treatment, quenching and tempering, tempering temperature and the cooling speed of the improper or deviation (Pi Ru cooling speed after tempering too slow), high temperature temper embrittlement; heat treatment surface decarburization phenomenon, the fatigue life of the disc spring adverse effects, so that the elastic limit and the fatigue life of the disc spring worse, is conducive to the formation of contributing to crack.
5 the use of environment to produce further embrittlement of disc spring. Disc spring in high or low temperature environment for a long time, the slow change, further embrittlement.
The use of 6 generation material embrittlement time. Material used for a long time, the disc spring internal organization to reach or even exceed the mechanical properties of the limit, embrittlement, premature fatigue failure.
Each of these factors can cause fatigue failure of disc spring in work, cause losses to the production and application, so the research of disc spring bear very has the application value relation between load and deformation, the calculation formulas of disc spring is suitable for medium and small load limits, explore the disc spring in the large load the relationship between stress and strain, the precision of calculation is very necessary.
1 due to the material composition is unreasonable, the composition segregation leads to disc spring performance is not uniform, for example, 60Si2Mn is used as the disc spring material, low content of Si, reduce the disk spring yield strength, resulting in embrittlement of parts occur in advance, and even cracking; P content was high, has exacerbated the brittle tendency of steel and component segregation and debris; the existence of segmentation of the continuity of the matrix crack, become sensitive, especially when the distribution in the surface of parts, easy to cause the stress concentration, stress crack corrosion preferred channel.
2 machining cracks. Disc spring processing by hot forging, quenching and high temperature tempering quenching and tempering treatment, shot peening, disc spring of internal micro cracks will appear in the whole process, resulting in stress concentration, in use process, if the load will accelerate the disc spring fatigue failure and crack.
3 stress corrosion. Disc spring when the tensile stress when the load is removed, the disc spring, the remained residual tensile stress of disc spring, if the long-term work in the acidic liquid or high humidity environment, in under the action of tensile stress in the solution of hydrogen aggregation, adsorbed on the surface of the hole, corrosion and other defects. The surface energy of atoms, or strong binding force reduction, the local stress concentration increases, when the crack nucleation energy is greater than the stress intensity factor at the crack tip, which leads to brittle fracture of crack nucleation and propagation environment, micro cracks appear, lead to premature fatigue failure of disc spring.
4 heat treatment is not reasonable. Disc spring heat treatment, quenching and tempering, tempering temperature and the cooling speed of the improper or deviation (Pi Ru cooling speed after tempering too slow), high temperature temper embrittlement; heat treatment surface decarburization phenomenon, the fatigue life of the disc spring adverse effects, so that the elastic limit and the fatigue life of the disc spring worse, is conducive to the formation of contributing to crack.
5 the use of environment to produce further embrittlement of disc spring. Disc spring in high or low temperature environment for a long time, the slow change, further embrittlement.
The use of 6 generation material embrittlement time. Material used for a long time, the disc spring internal organization to reach or even exceed the mechanical properties of the limit, embrittlement, premature fatigue failure.
Each of these factors can cause fatigue failure of disc spring in work, cause losses to the production and application, so the research of disc spring bear very has the application value relation between load and deformation, the calculation formulas of disc spring is suitable for medium and small load limits, explore the disc spring in the large load the relationship between stress and strain, the precision of calculation is very necessary.
