Intro - Corrosion Failures And Analysis

Summary

In this course, Kalol Mandal from IIT Kanpur explores various forms of corrosion and its impact on structures in different industries. He discusses examples from household items to naval structures, highlighting how corrosion can lead to severe failures. The course also covers protective measures against corrosion, including material changes, design modifications, and the use of inhibitors, aiming to provide a comprehensive understanding of corrosion and its prevention.

Takeaways

• 👨‍🏫 The course is led by Kalol Mandal, a faculty member in the Department of Materials Science and Engineering at IIT Kanpur.
• 🔬 The course covers the electrochemical nature of corrosion and mixed potential theory, building on previous lectures.
• 🌡️ High temperature corrosion, such as oxidation, is also discussed, highlighting its importance in various industries.
• 🏭 The course explores different forms of corrosion with examples from household, construction, petrochemical, naval, medical equipment, and implant industries.
• 🏗️ Corrosion can lead to severe structural failures, such as the rapid fracturing of a concrete pillar due to rusting iron fencing.
• 🍳 Household items like iron spatulas can also suffer from corrosion, especially in areas where they are folded or crevices are present.
• 🚪 Corrosion in household items is often observed in areas exposed to atmospheric effects like moisture, oxygen, rainwater, and even gravy.
• 🔐 Iron locks are prone to corrosion in crevices, especially where the key is inserted, due to their exposure to environmental factors.
• 🚴‍♂️ Bicycle parts, particularly crevices and bent portions, are susceptible to corrosion due to their exposure to the elements.
• 🌿 Accidental placement of corrosive substances, like fertilizer, can lead to unexpected and serious corrosion, as seen with an iron grid over an AC unit.
• 🛡️ The course aims to teach protection philosophies to prevent corrosion, including material changes, environmental modifications, and design alterations.
• 🛠️ Electrochemical methods of corrosion protection, coatings, and the use of inhibitors will also be discussed as ways to control corrosion.

Q & A

Who is the speaker in the script?

The speaker in the script is Kalol Mandal, a faculty member in the Department of Materials Science and Engineering at IIT Kanpur.

What topics were discussed in the previous lectures?

In the previous lectures, the electrochemical nature of corrosion, mixed potential theory, and oxidation under high-temperature corrosion were discussed.

What different forms of corrosion will be covered in the course?

The course will cover various forms of corrosion and will provide examples from household, construction, petrochemical, naval structures, medical equipment, and implants.

What is the significance of the pillar example mentioned in the script?

The pillar example illustrates how the preferential corrosion of iron fencing within the concrete can lead to hoop stress and ultimately cause the pillar to fracture.

Why does the iron spatula corrode preferentially along certain areas?

The iron spatula corrodes preferentially along certain areas due to the crevices formed by folding the sheet metal, which are more susceptible to atmospheric effects like moisture, oxygen, and rainwater.

What is the role of crevices in the corrosion process?

Crevices play a significant role in the corrosion process as they can trap moisture and create environments conducive to corrosion, leading to localized and accelerated corrosion.

How does the script relate the corrosion of iron locks to crevices?

The script indicates that the part of the iron lock where the key is inserted is a crevice and thus experiences more corrosion compared to other parts of the lock.

What is the connection between the bicycle handle and corrosion mentioned in the script?

The bicycle handle's crevices and bent portions are highlighted as areas where corrosion is more likely to occur due to the accumulation of moisture and debris.

What is the reason behind the corrosion of the iron grid over the window AC unit?

The iron grid over the window AC unit corroded because a gardener accidentally placed a highly corrosive fertilizer packet on top of it, leading to localized corrosion.

What strategies will the course discuss to prevent or control corrosion?

The course will discuss strategies such as material modification, environmental changes, design alterations, and the use of electrochemical methods like cathodic and anodic protection.

What role do coatings play in corrosion protection as mentioned in the script?

Coatings are highlighted as an excellent method to protect metals and alloys from corrosion by providing a barrier between the metal and the corrosive environment.

What is the significance of inhibitors in controlling corrosion?

Inhibitors, which can be organic or inorganic substances added to the electrolyte, play a crucial role in preventing or controlling corrosion by reducing the corrosion rate.