Carbon steel is a form of steel that is made of iron with carbon added. Alloy steel, on the other hand, is made of iron plus different materials to modify its properties. Carbon steel is stronger than alloy steel, but it is harder to weld than alloy steel. It is also more ductile than iron and is more corrosion-resistant. Alloy steel is stronger than carbon steel Despite their similar appearances, carbon steel and alloy steel have distinct differences. The former is more resistant to corrosion, while the latter is weaker. While both steels can be used to build structures, alloys have better machinability and are stronger than carbon steel. Alloy steels are also harder than carbon steel but have a lower hardness. Carbon steel contains between 0.96% and 2.1% carbon and is used for structural applications. Alloy steel, on the other hand, has more than 8% alloying element and is better for applications where strength is of primary concern. In addition to carbon, alloy steels also contain other elements such as silicon, manganese, sulfur, and phosphorus. Stainless steel is more corrosion resistant Stainless steel is more corrosion-resistant than other metals, but there are still some conditions that make it susceptible to corrosive attack. For example, high chloride content can cause the metal to corrode if it is exposed to water. This condition is called pitting corrosion and can lead to the deterioration of parts. However, the severity of this corrosion can be minimized by ensuring proper drainage, gaskets, and welding. Stainless steel can also corrode if it is exposed to high heat, which can reduce its passivation layer. Because stainless steel is more corrosion resistant, it is often used in applications that require excellent corrosion resistance. Stainless steel has a very thin oxide layer on its surface. This passive layer renders the steel surface electrochemically passive in corrosive environments. Carbon steel is harder to weld There are several reasons why carbon steel is harder to weld. High-carbon steel tends to be more brittle than low-carbon steel and can crack easily during the welding process. This material is best welded with a low-hydrogen electrode. However, it's important to note that it's not inherently impossible to weld with carbon steel. Welders who want to weld carbon steel must keep the weld heat low, limiting it to red-hot and not exceeding 400 degrees Celsius. This will minimize the likelihood of hydrogen-induced cracking. Welders should also avoid stringers and take special care at the root of the weld. The base metal should be thoroughly cleaned before welding to eliminate any porosity. It is more expensive There are two main types of steel: carbon and stainless. The cost of stainless steel is higher than that of carbon steel, but very high-carbon steel can be comparable in cost. It is important to understand which steel grade is best for your application, as it can affect the cost. The process used for making steel will also have an effect on the cost. Steel can be created in a variety of ways, including scrap melting or an electric arc furnace. To create medium or high-carbon steel, for example, the steelmaker might have to add additional carbon to make the steel.