Service Hotline: |
By analyzing the macro micro features of the internal surface cracks of the machining of the alloy shell parts the processing of the parts, the cause of failure is finally found out improvement measures are proposed.
Through the analysis of the chemical composition of the broken parts of the failed parts, the content of each element meets the requirements of the relevant standards, so the possibility of cracking of the inner surface of the part caused by the raw material mixture is excluded.
The low-magnification corrosion test results of the faulty parts rule out the possibility that the raw materials will crack due to severe metallurgical defects.
Aiming at the problem of crack defects appearing on the processing inner wall of this shell part, its processing technology flow was analyzed in detail. The original processing technology of 2A12 aluminum alloy shell parts is: blanking → car center hole (Ф65) → heat treatment (quenching + natural failure) → car inner hole (Ф140) → failure. The wall thickness of parts before heat treatment reaches 92.5mm.
The metallographic analysis of the heat-treated (quenched + natural failure) faulted parts shows that the reason for the cracks on the inner wall of the shell parts is due to the excessive wall thickness insufficient heat treatment.
According to the actual situation of the raw materials of aluminum alloy shell parts, the heat treatment process is further optimized, quenching + artificial aging heat treatment. Pit-type furnace is heated to 495 ± 5 ℃, heat preservation is 180 ~ 210min, water cooling. No over-firing was found in the microstructure, the phenomenon of aggregation of strengthened phases along grain boundaries was significantly improved. This proves that the cracking part of the inner surface of the part is caused by insufficient heat treatment.
The analysis of the processing technology of the faulty parts shows that when processing to the insufficient heat treatment position, then maintain the previous cutting speed cutting amount, the stress at the tool tip is concentrated on the grain boundary strengthening phase aggregation, resulting in the crack distribution along the strengthening phase The direction is expanding rapidly.
By analyzing the macro micro characteristics of the internal surface cracks of the alloy shell parts the processing of the parts, the cause of failure is finally found out improvement measures are proposed.
Through the analysis of the chemical composition of the broken parts of the failed parts, the content of each element meets the requirements of the relevant standards, so the possibility of cracking of the inner surface of the part caused by the raw material mixture is excluded.
The low-magnification corrosion test results of the faulty parts rule out the possibility that the raw materials will crack due to severe metallurgical defects.
Address: Building F3, Tianyou Chuangke Industrial Park, No. 2 Lixin Road, Fuhai Street, Baoan District, Shenzhen | |
Mobile phone:13825275151 | |
mailbox:maker@hw-robots.com | |
phone:0755-85275462 |