Document Type : Research Paper

Authors

• Ahmed Kamil Ghadeer ¹
• Ekbal M. Seed ²
• Hayder A.H. ALguboori ²

¹ Department of Construction and Projects, University Presidency, Thi-Qar of University, Iraq

² Department of Metallurgical Engineering, College of Materials Engineering, University of Babylon, Iraq

Abstract

Corrosion that occurs in concentrated sulfuric acid production plants causes damage to equipment, pipes, tanks, and pumps, which affects the cost of maintenance time, which causes production stoppage and danger to workers due to the high acid concentration. The researchers used several types of alloys that help sustain production with different protection methods. Some of them are expensive, and some are highly corrosive, such as iron alloys, nickel alloys, polymers, and others in factory equipment. The current work is devoted to obtaining an alloy with mechanical and corrosive properties comparable to what is used in the concentrated sulfuric acid production plant in Iraq and the world to be used in the most important components of pipes and tanks to preserve the concentrated acid in the factory. Various alloys of a group of elements with an iron base were used and produced by the powders metallurgy method to achieve this purpose. Mechanical, corrosion tests and inspection (hardness, microstructure, dry slip corrosion, wear/abrasion, slight immersion, and Tafel testing were performed, XRD, EDX, SEM)
The alloys used in this research are:
$$\mathrm{A} 1(1 \% \mathrm{Cr}+1 \% \mathrm{Ni}+1 \% \mathrm{Mo}+0.5 \% \mathrm{Cu}+0.5 \% \mathrm{Si}+0.1 \% \mathrm{~W}+0.1 \% \mathrm{Ti}+1 \% \mathrm{Mn}) $$
$$\mathrm{A} 2(1 \% \mathrm{Cr}+1 \% \mathrm{Ni}+1.5 \% \mathrm{Mo}+1.5 \% \mathrm{Cu}+1 \% \mathrm{Si}+0.2 \% \mathrm{~W}+0.2 \% \mathrm{Ti}+1 \% \mathrm{Mn}) $$
$$ \mathrm{A} 3(2 \% \mathrm{Cr}+2 \% \mathrm{Ni}+2 \% \mathrm{Mo}+2.5 \% \mathrm{Cu}+0.5 \% \mathrm{Si}+0.2 \% \mathrm{~W}+0.2 \% \mathrm{Ti}+2 \% \mathrm{Mn}) $$
$$ \mathrm{A} 4(2 \% \mathrm{Cr}+2 \% \mathrm{Ni}+1 \% \mathrm{Mo}+3.5 \% \mathrm{Cu}+1 \% \mathrm{Si}+0.2 \% \mathrm{~W}+0.3 \% \mathrm{Ti}+2 \% \mathrm{Mn})$$
$$ \mathrm{A} 5(3 \% \mathrm{Cr}+3.5 \% \mathrm{Ni}+1.5 \% \mathrm{Mo}+4 \% \mathrm{Cu}+0.5 \% \mathrm{Si}+0.5 \% \mathrm{~W}+0.5 \% \mathrm{Ti}+3 \% \mathrm{Mn}) $$
$$ \mathrm{A} 6(3 \% \mathrm{Cr}+3 \% \mathrm{Ni}+2 \% \mathrm{Mo}+3 \% \mathrm{Cu}+0.5 \% \mathrm{Si}+1 \% \mathrm{~W}+1 \% \mathrm{Ti}+3 \% \mathrm{Mn}) $$
$$ \mathrm{A} 7(4 \% \mathrm{Cr}+4 \% \mathrm{Ni}+1 \% \mathrm{Mo}+4 \% \mathrm{Cu}+1 \% \mathrm{Si}+2 \% \mathrm{~W}+1.5 \% \mathrm{Ti}+2 \% \mathrm{Mn}) $$
$$ \mathrm{A} 8(5 \% \mathrm{Cr}+5 \% \mathrm{Ni}+1.5 \% \mathrm{Mo}+3 \% \mathrm{Cu}+1 \% \mathrm{Si}+1.5 \% \mathrm{~W}+2 \% \mathrm{Ti}+3 \% \mathrm{Mn}) $$
$$ \mathrm{A} 9(5 \% \mathrm{Cr}+5 \% \mathrm{Ni}+2 \% \mathrm{Mo}+4 \% \mathrm{Cu}+0.5 \% \mathrm{Si}+2 \% \mathrm{~W}+3 \% \mathrm{Ti}+3 \% \mathrm{Mn}) $$
$$ \mathrm{A} 10(5 \% \mathrm{Cr}+5 \% \mathrm{Ni}+1.5 \% \mathrm{Mo}+3 \% \mathrm{Cu}+1 \% \mathrm{Si}+3 \% \mathrm{~W}+2 \% \mathrm{Ti}+2 \% \mathrm{Mn})$$
Compared to the reference samples, an increase in corrosion resistance, hardness, and wear was observed in A9 and A10 alloy. The corrosion rate (corrosion/corrosion) of the alloy improved by a factor of (40 to 99) % compared to the reference samples (carbon steel, stainless steel 304, alloy 310). / 310S / 310H), and A9, A10 compared to (ZERON, 100 alloys Sandvik SX, ZECOR, SARAMET 23 and 35, improving (13%) A9 and (0.8%) A10. In simple immersion, the primary carbon steel alloys suffered from corrosion compared to improving the alloy (A1 to A10); the improvement percentage was more than (99) \%. Alloys (ZERON, ZECOR, Stainless Steel 304l), the improvement percentage in alloys only (A9, A10) from (24 to 55) %. The polarization test (Tafel) in concentrated acid on the alloy (A9 to A10) showed that the corrosion resistance of concentrated sulfuric acid was much better than that of carbon steel with a very high percentage. The improvement was about (99) % compared to carbon steel. Alloy A9 was the best in improving the resistance of carbon steel. Corrosion in all equipment and parts of the concentrated sulfuric acid plant (98%).

Keywords

• (Corrosion
• Sulfuric Acid
• Alloys Elements
• Coating
• Cathodic and Anodic Protection
• Or Appropriate Design
• Powder Metallurgy
• Mixing
• Compacting
• Sintering
• XRD
• EDX
• Tafel
• Hardness
• Wear)