The use of Al- Zn alloys as sacrificial anodes to protect buried steel pipes

Dissertant

Abd al-Sahib, Yasir Muhyi

Thesis advisor

al-Haydari, Jafar Tahir
Hafiz, Muhammad H.

University

University of Technology

Faculty

-

Department

Department of Production Engineering and Metallurgy

University Country

Iraq

Degree

Master

Degree Date

2010

English Abstract

Corrosion is the main problem in the embedded pipelines in different environment resistivity's.

The most effective method to overcome this problem is catholic protection which represents a best control method in the pipe corrosion.

Corrosion protections of these structures are complex phenomena.

Both catholic protection technique i.e, impressed current or sacrificial anodes are required to develop a complete understanding of the underlying basics of corrosion science as well as understanding of the system level behavior and the parameters that affect the process In this work some rational strategies for achieving the desired life.

Extension of the external corrosion control system and evaluating the life and capacity of aluminum alloys were used in sacrificial anodes to protect the embedded carbon steel pipe in different simulated resistivity of soils in Iraq of 25, 50, 600, 1000 and 5000 ohm.cm.

The anodes were alloyed as (Al-5 % Zn), (Al-10 % Zn) and (Al-15 % Zn) due to their high potential in this environment resistivity which are simulated by different concentration from salt (NaCl) solutions without any effect of bacteria and obstacles.

From this work were find the relationships between the protection potential with times, sacrificial anode life, discharge currents and capacity of sacrificial anodes in different solution resistivity, distance between sacrificial anode and protected steel pipe.

Corrosion rate, current density and microstructure for these three types of sacrificial anodes, in addition to the polarization phenomena in 3.5 %.

NaCl solution salt was studied.

Also Corrosion rate of sacrificial anodes by weight loss methods (open circuit potential test) for 180 days were also studied.

On the other hand experimental work was carried out to collect the required data to be used for performance evaluation of various sacrificial anodes in catholic protection system designed for Iraqi soil.

According to the results obtained the anode alloy (Al-10 % Zn) has the best anode capacity in resistivity 25, 50 and 600 its 2482, 3407 and 333 A.hr / Kg respectively and life 5.7, 7.6 and 11.4 years respectively compared with other anodes in these conditions.

Main Subjects

Materials Science , Minerals

Topics

• Zinc alloys

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305094