scholarly journals EFFECT OF ANIONS IN SEAWATER TO CORROSION ATTACK ON PASSIVE ALLOYS

2013 ◽  
Vol 02 (12) ◽  
pp. 733-737 ◽  
Author(s):  
A. Ismail .
Keyword(s):  
Corrosion Attack ◽  
Passive Alloys

Kerusakan Pada Material Pipa Air Bersih Akibat General Corrosion

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
M. N. Setia Nusa
Keyword(s):  
Chemical Composition ◽  
Failure Analysis ◽  
External Surface ◽  
Internal Surface ◽  
General Corrosion ◽  
Water Pipe ◽  
Corrosion Attack ◽  
Corrosion Failure ◽  
Environment Factor

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

Effect of corrosion attack on the fatigue behavior of an as-cast Mg–7%Gd–5%Y–1%Nd–0.5%Zr alloy

2015 ◽  
Vol 84 ◽  
pp. 185-193 ◽  
Author(s):  
S.D. Wang ◽  
D.K. Xu ◽  
B.J. Wang ◽  
E.H. Han ◽  
C. Dong
Keyword(s):  
Fatigue Behavior ◽  
Corrosion Attack ◽  
Zr Alloy

scholarly journals Serangan Korosi Sumuran pada Tube Heat Exchanger di Kilang Pengolahan Minyak

2019 ◽  
Vol 8 (3) ◽  
pp. 107-114
Author(s):  
Hadi Sunandrio ◽  
Sutarjo
Keyword(s):  
Heat Exchanger ◽  
Pitting Corrosion ◽  
Visual Inspection ◽  
Outer Tube ◽  
Oil Refinery ◽  
Composition Analysis ◽  
Heat Exchanger Tube ◽  
Corrosion Attack ◽  
Tube Heat Exchanger ◽  
Exchanger Tube

Alat penukar panas (Heat Exchanger) adalah suatu alat yang berfungsi untuk menaikkan temperatur. Apabila salah satu komponen dari Heat Exchangertersebut mengalami kerusakan, maka temperatur yang diinginkan tidak akan tercapai. Salah satu dari tube heat exchanger yang ada di Kilang Pengolahan Minyak mengalami kerusakan berupa putus akibat terkorosi. Setelah dilakukan pemeriksaan dan pengujian yang meliputi : pemeriksaan visual, metalografi, uji kekerasan, analisa komposisi kimia, dan analisa EDAX. Maka diketahui bahwatube Heat Exchanger telah mengalami serangan korosi sumuran (pitting corrosion) pada permukaan dalam dan luar tube. Terjadinya serangan korosi sumuran, karena pada permukaan dalam dan luar tube terlapisi oleh deposit yang cukup tebal dan mengandung unsur-unsur Sulphur (S) dan Chlor (Cl) yang dapat memicu timbulnya serangan korosi sumuran (pitting corrosion), hingga tube mengalami penipisan di mana-mana dan putus.Kata kunci : Alat penukar panas, Tube, Endapan, Korosi sumuran, putus.AbstractHeat exchangers is a tool that serves to raise the temperature. If one component of the Heat Exchanger is damaged, then the desired temperature will not be reached. One of the tube heat exchanger that is in Oil Refinery suffered damage in the form of broken due to corroded. After examination and testing that includes visual inspection, metallography, hardness testing, chemical composition analysis, and analysis of EDAX. It is known that the tube Heat Exchanger has suffered attacks pitting corrosion on the surface of the inner and outer tube. Pitting corrosion attack, because the surface of inner and outer tube coated by a deposit that is thick and contains elements of Sulphur (S) and Chlor (Cl) which can lead to pitting corrosion attack, to experience thinning tube where everywhere and brokenKeyword : Heat exchanger, Tube, Deposit, Pitting corrosion, Broken.

scholarly journals Variability of Local Corrosion Attack Morphology of AISI 316Ti Stainless Steel in Aggressive Chloride Environment

2014 ◽  
Vol 14 (3) ◽  
pp. 493-497 ◽  
Author(s):  
Viera Zatkalíková ◽  
Lenka Markovičová ◽  
Juraj Belan ◽  
Tatiana Liptáková
Keyword(s):  
Stainless Steel ◽  
Local Corrosion ◽  
Corrosion Attack ◽  
Chloride Environment

Effect of solution aggressiveness on the crack - growth resistance and cracking mechanism of AA2024-T3

CORROSION ◽  
10.5006/3839 ◽  
2021 ◽  
Author(s):  
Christina Charalampidou ◽  
Christiaan Pretorius ◽  
Roelf Mostert ◽  
Nikolaos Alexopoulos
Keyword(s):  
Grain Boundary ◽  
Crack Growth ◽  
Compact Tension ◽  
Crack Growth Resistance ◽  
Corrosion Attack ◽  
Secondary Cracks ◽  
Cracking Mechanism ◽  
Grain Boundary Embrittlement ◽  
Corrosive Environments ◽  
Boundary Embrittlement

Aluminium alloy 2024-T3 was examined – using a range of microscopy techniques – at the early stages of corrosion attack to investigate the corrosion-induced cracking mechanism. Two different corrosive environments, exfoliation corrosion (EXCO) and 3.5 % wt. NaCl, were used for the exposure of tensile and pre-notched compact-tension C(T) specimens of AA2024-T3. Different embrittlement mechanisms are noticed for the two investigated corrosive environments. Significant intergranular corrosion (IGC) and grain boundary embrittlement is evident in the specimens exposed to EXCO solution, while this was not the case for the milder solution; comprising of 3.5 % wt. NaCl. With regards to the milder solution, corrosion attack is not restricted to the grain boundary, but evolves transgranularly to the neighbouring grains of the IGC attacked region and, consequently, the grain boundary strength in the direct vicinity is not notably affected. The extent of secondary cracks – after the exposure of C(T) specimens to EXCO solution and the subsequent crack-growth resistance evaluation – were found to correlate with the diameter of the plastically affected zone (≈ 3.78 ± 0.04 mm). Additionally, the depth of these cracks was found to correlate well with the thickness of the intergranular fracture surface, giving evidence that the secondary cracks form due to grain boundary embrittlement; probably attributed to hydrogen embrittlement phenomena.

Microstructural and Corrosion Studies by Immersion in 3.5% NaCl Solution on Aged Mg-9Al-1Zn-XCa Alloy

2019 ◽  
Vol 969 ◽  
pp. 93-97
Author(s):  
S. Manivannan ◽  
B. Narenthiran ◽  
A. Sivanantham ◽  
S.P. Kumaresh Babu
Keyword(s):  
Corrosion Behaviour ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Corrosion Attack ◽  
X Ray ◽  
Α Phase ◽  
Corrosion Studies ◽  
Different Temperatures ◽  
Xrd Techniques ◽  
Scanning Electron

The experimatal alloys were aged at different temperatures of 180°C, 200°C, 220°C, and 240º C with calcium addition levels of (X=0.5, 1, 1.5, 2%) on Mg-6Al-1Zn-XCa alloy were investigated in 3.5% NaCl solution. All the experimatal alloys were immersed in 3.5% NaCl solutions and the resulted surface were analyzed to study the corrosion behaviour and its surface topography by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersed spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The result shows that corrosion attack occurred predominantly on ß phase and α phase exhibit relatively minor corrosion. In addition to that the increased aging temperature coarsens the intermetallic as well as α- Mg grains, which shows adverse effect to corrosion resistances and the best result were obtained at composition of 0.5wt.% Ca aged at 200°C.

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