A piece of corroded steel plate was found in a submerged ocean vessel. It was estimated that the original area of the plate was 10 in. \(^{2}\) and that approximately \(2.6 \mathrm{~kg}\) had corroded away during the submersion. Assuming a corrosion penetration rate of \(200 \mathrm{mpy}\) for this alloy in seawater, estimate the time of submersion in years. The density of steel is \(7.9 \mathrm{~g} / \mathrm{cm}^{3}\)

Material degradation, specifically referring to metals such as steel, is a process where the material's quality deteriorates due to environmental factors. One common type of degradation is corrosion, which happens when metal reacts with its environment, leading to the loss of material. In the case of our corroded steel plate, the sea water has caused the metal to corrode away, reducing its mass over time.

Understanding the rate at which this corrosion occurs is crucial for predicting the lifespan of metal structures and components. For instance, in the exercise given, knowing the original mass and the corrosion penetration rate allows us to calculate the time the steel plate had been submerged. By examining material degradation, we can make informed decisions about maintenance, repairs, and replacements necessary to ensure the safety and integrity of structures like ocean vessels.

The relationship between density and volume is vital when studying material properties and their changes over time. Density is defined as the mass of an object divided by its volume. This characteristic helps us determine how much space a certain mass of material occupies, which is particularly useful in corrosion studies.

In the context of our corroded steel plate, we use this relationship to calculate the volume of steel that has been lost to corrosion. With the knowledge of the material's mass and its density, we can find out the volume that the missing 2.6 kg of steel would occupy. This calculation is critical for the next step—determining how much the steel plate has thinned over time due to corrosive forces. Hence, understanding density and volume relationships is not only foundational for solving this problem but also pivotal for applications in engineering and materials science.

In scientific calculations, especially in a global context, it’s often necessary to convert between different measurement units. Since different countries and industries use various units to measure length, mass, and volume, the ability to convert these units accurately is essential to ensure clear communication and accurate results.

Throughout the exercise we encounter different units such as kilograms, grams, centimeters squared, inches squared, centimeters, mils (thousandths of an inch), and years. Correctly converting these units is the only way to compare and calculate variables like mass, volume, and thickness. In particular, the conversion from centimeters to mils allows us to use the corrosion penetration rate given in mils per year. This step is crucial to determine the time of submersion in years correctly. Without a firm understanding of unit conversion, calculations and comparisons in many fields of science and engineering would be prone to significant errors.