Vibration aging equipment to deal with welding residual stress of tank connection

After the reinforcement of the bottom tank wall of the large tank, there is often a large stress concentration in the welding area, which will adversely affect the long-term safe use of the tank. After the oil tank is welded, the stress relief treatment must be carried out. The JH-600A liquid crystal AC vibration aging equipment is used for the stress relief treatment of the tank connection. The reasonable vibration aging treatment process is adopted, and the actual application is achieved through the actual application. effect.

Tank aging on-site vibration aging treatment

Vibration aging equipment. The JH-600A liquid crystal AC vibration aging equipment produced by Nanjing Juhang Technology Co., Ltd. was used for vibration treatment.

The installation of vibration aging equipment. According to the different forms of the tank connection, the corresponding tooling is made, and the vibration aging equipment is rigidly fixed to the appropriate part of the nozzle by using the clamp.

The choice of exciting force. Excitation force is a key parameter in vibration aging, especially for welded components. The exciting force should be such that the dynamic stress generated by it is equal to 1/2 times the working load of the component, and the exciting force is determined by the eccentric gear and the resonant frequency of the exciter. When the frequency of the resonance determines the resonant frequency, Determine the appropriate eccentric gear to satisfy the above relationship. Proper selection of the exciting force not only reduces the residual stress, but also improves the fatigue life of the welded component. The excitation time was chosen to be 30 min.

Economic effect analysis of vibration aging treatment technology

technical analysis. In order to further verify the vibration treatment effect of the welding residual stress at the take-over part, the stress test of the reinforcing weld and the joint weld of the tank take-up was carried out. The test work was completed by the professionals of Nanjing Juhang Technology Co., Ltd. The test uses the blind hole method to test the residual stress of the workpiece after the vibration. According to the test results, the weld residual stress of the weld zone of each specification is obviously reduced after the vibration aging treatment, and the drop rate meets the index requirement of more than 30% as specified by the standard. Therefore, it can be considered that the selected process parameters are used for the take-over pipe. The vibration stress relief process achieves the vibration aging process effect.

Economic effect analysis. The vibration aging treatment process of the oil storage tank is reduced by about 81.4% compared with the conventional heat treatment process, the power consumption is reduced by more than 98%, and the single processing time is reduced. Therefore, vibration aging treatment is an efficient and energy-saving stress relieving treatment method, and it has significant economic benefits in place of traditional heat treatment.

The welding residual stress treatment is carried out by the vibration aging process, and the main stress elimination rate can reach 30% to 60%, meeting the requirements of the national standard.

The large-scale storage tank take-up weld adopts vibration aging treatment compared with conventional heat treatment, and the equipment is simple, the operation is convenient and saves a lot of man-hours, and the comprehensive treatment cost can be greatly reduced.

Using JH-600 liquid crystal AC vibration aging equipment not only reduces residual stress, but also improves the fatigue life of welded components.

The vibration aging treatment can replace the conventional heat treatment for the welding residual stress treatment of the large tank connection pipe, and has significant economic benefits.