Effect of Fungus, Aspergillus sp. F1-1, on the Corrosion Behavior of PCB-HASL in Humid Atmospheric Environment

2021 ◽  
Author(s):  
Yuting Hu ◽  
Kui Xiao ◽  
Lidan Yan ◽  
Xiangping Hao ◽  
Luyao Huang ◽  
...  
Keyword(s):  
Service Life ◽  
Corrosion Behavior ◽  
Electronic Materials ◽  
Microbiologically Influenced Corrosion ◽  
Atmospheric Environment ◽  
Exposure Test ◽  
Surface Cracking ◽  
Micro Hole ◽  
Metabolic Activities ◽  
Aspergillus Sp

Abstract Fungi, as one of the serious factors causing microbiologically influenced corrosion (MIC), can shorten the service life of electronic materials which are wildly used in the atmospheric environment. In this study, the effect of Aspergillus sp. F1-1 (A. F1-1) isolated from PCB samples after the exposure test in Xishuang Banna on the corrosion behavior of PCB-HASL was investigated. The presence of the A. F1-1 posed a threat of local corrosion on PCB-HASLs. An obvious decrease of pH was observed in PCB with A. F1-1 due to the various organic acids secreted by A. F1-1. The presence of the fungi also led to serious surface cracking and delamination. Creep corrosion and micro-hole corrosion were accelerated in the presence of A. F1-1 compared to the control. Additionally, the metabolic activities of A. F1-1 were associated with enrichment of Cu-containing corrosion products under the hypha.

Study on Corrosion Behavior of Stainless Steel in Atmospheric Environment by Exposure Test

2021 ◽  
Vol 70 (7) ◽  
pp. 228-236
Author(s):  
Tomohiro Ishii ◽  
Masataka Omoda ◽  
Reiko Sugihara ◽  
Misako Tochihara ◽  
Le Thi Hong Lien ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Behavior ◽  
Atmospheric Environment ◽  
Exposure Test

Turbidity Method to Measure the Growth of Anaerobic Bacteria Related to Microbiologically Influenced Corrosion

2015 ◽  
Vol 227 ◽  
pp. 298-301
Author(s):  
Akrima Abu Bakar ◽  
Rosilawati Mohd Rasol ◽  
Yahaya Nordin ◽  
Norhazilan Md Noor ◽  
Muhammad Khairool Fahmy bin Mohd Ali
Keyword(s):  
Anaerobic Bacteria ◽  
Cell Number ◽  
Counting Efficiency ◽  
Microbiologically Influenced Corrosion ◽  
Desulfovibrio Vulgaris ◽  
Bacteria Growth ◽  
Cell Numbers ◽  
Graph Pattern ◽  
Metabolic Activities ◽  
Turbidity Method

This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria growth can accelerate the corrosion process and shorten the reliability of pipelines. Thus, the investigation of MIC species’ development and metabolic activities is significant. An experiment was performed on sulfate-reducing bacteria (SRB) that practiced the medium as the substance to grow. Desulfovibrio vulgaris, a strain of SRB, was cultured in a postgate C medium to measure the bacteria survival using two different measurement methods. The medium was modified to pH 7.5 at 37°C and placed in anaerobic vials. During 24 hours of incubation, samples were retrieved, and the value of turbidity and cell numbers was measured. Based on the SRB growth graph pattern, the amount of bacteria cell numbers was increased parallel to the value of the medium’s turbidity in respect to time. Both values (turbidity and bacteria cell numbers) dramatically increased from hour1 to hour24. The results supported that the turbidity value was positively correlated with bacteria cell numbers.

scholarly journals Corrosion Behavior of Corrosion-Resistant Spring Steel Used in High Speed Railway

2021 ◽  
Vol 11 (18) ◽  
pp. 8668
Author(s):  
Jinbo Li ◽  
Ziying Zhu ◽  
Hongwei Chen ◽  
Shaojie Li ◽  
Hongyan Wu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
High Speed ◽  
Corrosion Potential ◽  
Early Stage ◽  
Corrosion Current ◽  
Corrosion Products ◽  
Atmospheric Environment ◽  
Rust Layer ◽  
Experimental Steel

Corrosion behavior of 60Si2Mn-A and 60Si2Mn-B in simulated industrial atmospheric environment was investigated by alternate immersion corrosion test and electrochemical method. The phase, morphology, characteristics of corrosion products, and the distribution of Cr, Cu, and Ni in the corrosion products of experimental steel were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA). The results show that the phase of rust layer is Fe3O4 and γ-FeOOH in the early stage and then changes to α-FeOOH and γ-FeOOH in the later stage; the size of the rust layer with corrosion resistance of 60Si2Mn is less than 60Si2Mn; the Cr element accumulates in the rust layer of the experimental steel in the early stage of corrosion resistance; and Cu, Ni, and Cr in the corrosion resistance 60Si2Mn are concentrated in the rust layer near the substrate In the later stage of corrosion. As the corrosion cycle is prolonged, the corrosion potential and the resistance of the rust layer of the experimental steel increases, and the corrosion current decreases; in the same corrosion cycle, the corrosion potential and corrosion resistance of 60Si2Mn-B are greater than 60Si2Mn, and the corrosion current is less than 60Si2Mn.

scholarly journals Initial Corrosion Behavior of Spheroidal Graphite Cast Iron in Atmospheric Environment

2020 ◽  
Vol 69 (5) ◽  
pp. 140-147
Author(s):  
Ichiro Dote ◽  
Yuuki Kuwahara ◽  
Nobuhiro Kai ◽  
Shigenobu Kainuma
Keyword(s):  
Cast Iron ◽  
Corrosion Behavior ◽  
Atmospheric Environment ◽  
Spheroidal Graphite ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron
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