2019 ◽  
Vol 16 (2) ◽  
Author(s):  
M. N. Setia Nusa

Water pipe of 4.5” diameter and has been operated for 8 year having failure due to corrosion attack on its external and internal surface. It is conducted failure analysis to find out the cause of corrosion by having testing examination of visual fractography, metalography,, SEM EDAX, hardness and chemical composition. Testing and examination results show that the failure / corroded pipe has a for in of general corrosion on the external surface due to environment factor or ground factor arround the pipe and on the internal surface was influenced by excessive root weld creating protrude which then causing turbolens and deposite to accelerate corrosion attack.Pipa berdiameter 4.5” yang berfungsi mengalirkan air bersih dan telah beroperasi selama 8 tahun, terjadi kerusakan berbentuk korosi pada permukaan luar pipa dan permukaan dalam. Untuk itu dilakukan analisa kerusakan untuk mengetahui penyebab terjadinya korosi dengan pengujian dan pemeriksaan secara visual,Fractography, Metallography, SEM, EDAX, Uji Kekerasan dan Uji Komposisi Kimia. Hasil pemeriksaan dan pengujian pada pipa yang rusak / korosi berbentuk jenis general korosi pada permukaan luar pipa yang diakibatkan faktor lingkungan atau tanah disekitar pipa, sedangkan pada bagian dalam pipa dipengaruhi oleh adanya lelehan pengelasan yang kurang sempurna sehingga menimbulkan benjolan yang mengakibatkan aliran air didalam pipa tidak lancar sehingga terjadi turbolensi yang menimbulkan endapan dan mengakibatkan percepatan terjadinya korosi.Keywords: Pipe, environtment, turbolens, corrosion, failure


Author(s):  
Dongmei Meng ◽  
Laura Buck ◽  
James Cargo

Abstract Cu needs a higher level of ultrasound combined with bonding force to be bonded to the Al pad properly, not just because Cu is harder than Au, but it is also harder to initiate intermetallic compounds (IMC) formation during bonding. This increases the chances of damaging the metal/low k stack under the bondpad. This paper presents a fundamental study of IMC as well as one example of a failure mode of Cu/Al bonded devices, all based on detailed analysis using scanning electron microscopy, scanning transmission electron microscopy, energy dispersive spectrometers, and transmission electron microscopy. It presents a case study showing a corrosion mechanism of Cu/Al ballbond after 168hr UHAST stress. It is observed that all Cu9Al4 was consumed, while very little copper aluminide remained after 168 hours of UHAST stressing.


Author(s):  
Hua Wu ◽  
Chencheng Huang ◽  
Ninghua Wen ◽  
Ting Mao ◽  
Shiping Tao ◽  
...  
Keyword(s):  

Author(s):  
Xiaofei Liu ◽  
Haiyan Zhu ◽  
Chenyang Yu ◽  
Haozhe Jin ◽  
Chao Wang ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Ping Zhang ◽  
Yafei Shi ◽  
Hanqing Zhao ◽  
Fulin Zhang ◽  
Guoqiang Zhang ◽  
...  

Stress corrosion cracking behavior of 4340 steel in oxygen-containing or chloride containing aqueous solution was researched, the tensile experiment results indicated 100°C deaerated distilled water, the rupture of 4340 steel mainly belongs to ductile fracture, the addition of oxygen or chloride would increase the SCC tendency of 4340 steel and transformed the rupture mechanism from ductile fracture to brittle rupture, the existence of oxygen or chloride would decreaseKISCCof 4340 steel in 100°C aqueous solution slightly, the simultaneous action of oxygen and chloride existed, and the simultaneous action would further increase the SCC tendency of 4340 steel in aqueous solution.


1988 ◽  
Vol 37 (10) ◽  
pp. 608-613
Author(s):  
Toshinori Ozaki ◽  
Ichiro Gyobu ◽  
Yuichi Ishikawa

2015 ◽  
Vol 15 (4) ◽  
pp. 541-547 ◽  
Author(s):  
D. Ifezue ◽  
F. H. Tobins

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