Iron is an incredibly useful and abundant metal that has been smelted and forged for nearly 4 millennia. Its modern applications are even more diversified than those in antiquity and can be found in both everyday and industrial products with a variety of shapes and sizes. Steel is an alloy of iron that has been mixed with other elements to make it hard, durable, and resistant to wear, rust, and corrosion. It is extremely strong, usually much lighter than cast iron, and resistant to compressive forces. Steel is made by combining iron ore, coke, and limestone at very high temperatures in a furnace called a blast furnace.
The most important properties of steel are its strength and hardness. The two main types of steel that are used in modern engineering and construction applications are carbon steel and alloy steel. Carbon steel is made by adding small amounts of carbon to iron and can range from very soft, ductile low-carbon steels to hardening, high-carbon steels. Alloy steel is made by adding other materials like chromium, nickel, copper, and molybdenum to iron and is used for much tougher applications than carbon steel.
The hardness of steel is determined by its carbon content and the amount of heat treated it undergoes. Through heat treatment, the steel is made tougher and harder as its molecules become more densely packed and connect more strongly. The more carbon that is added to the steel, the stronger and harder it will be. This is why high-grade stainless steel knives and tools are usually made with more carbon than low-grade steel. The iron-carbon ratio, or iron to carbon ratio, is the measurement used to determine the ratio of iron to carbon in a steel alloy.
The iron-carbon ratio is one of the main factors that affect the strength of steel. The higher the iron-carbon ratio, the stronger and harder the steel will be. Generally, the desirable values for iron-carbon ratio depend on the type of steel and its intended use. Low-carbon steels have high iron-carbon ratios and are used for applications that do not require high strength or wear resistance. High-carbon steels have lower iron-carbon ratios and are used for applications that require more strength and durability. The iron-carbon ratio also affects the cost of steel, as steel with more iron is cheaper than steel with higher carbon content.
Overall, the iron-carbon ratio is an important factor to consider when buying or using steel. It determines the strength, hardness, and cost of the steel and must be chosen based on its intended use. When the right iron-carbon ratio is selected, steel can be an incredibly strong and versatile material that can be used for a variety of applications.
