Difference Between Mild Steel and Stainless Steel

Mild Steel vs Stainless Steel

Steel can be categorized as an alloy. An alloy is made by mixing two or more elements, where at least one of it is a metal. Generally steel is obtained by mixing carbon mainly and other elements in trace amounts with iron in order to obtain several productive properties rather than using iron as a plain metal. These elements are usually mixed according to weight percentages and depending on the amounts of these mixed elements steel can be easily divided into many grades. Carbon steel and stainless steel are the most common of them.

Mild Steel

Mild steel is the mildest type of carbon steel, having a comparatively low amount of carbon which scales up to 0.25% in its maximum. Carbon acts as a hardening agent. Mild steel can also have other elements such as manganese, silicon close to 0.5% in weight and trace amounts of phosphorous. These added elements protect the integrity of the structure of metal iron by preventing dislocations within the iron crystals.

Mild steel is the most common form of steel and is used in 85% of all steel products, in the United States alone. Other desirable properties of it include not being brittle, being stronger than iron, and also being cheap. The strength of steel generally increases with the percentage of carbon added. Mild steel is often used to produce steel sheets, wires and other building material.

Stainless Steel

Stainless steel has earned its name by the property of being non-corrosive. This special feature is due to other metals added to iron; close to 18% of chromium and 8% of nickel. The amount of iron included roughly sums up to 73% of the total weight. Stainless steel also includes close to 0.3% of carbon. Highlighting on its non-corrosive nature, stainless steel is been commonly used in kitchenware, in making scissor blades, wristwatch bands, also in the manufacturing of automobile parts, aerospace structures, and large building structures.

Iron when in contact with air and moisture tends to rust. Here, iron oxidizes to form “iron oxide”. In the case of stainless steel, chromium acts as a passive film around the iron core forming “chromium oxide”, which prevents further surface corrosion and also the spreading of corrosion to the internal iron core. This process is known as “passivation” where a metal becomes passive towards the effects of its environment, especially when there’s an outer layer shielding the metal from corrosion. Passivation is an important process that strengthens and preserves the appearance of metals raising them higher in value.

What is the difference between Mild Steel and Stainless Steel?

• Stainless steel mainly differs from mild steel (carbon steel) in composition, by the amount of chromium present.

• Stainless steel is resistant towards corrosion whereas mild steel readily corrodes and rusts when exposed to air and moisture.

• Stainless steel is more formable in character while mild steel is rigid and tough.

• Chromium is generally rated as a heavy metal. Therefore, due to the inclusion of chromium, stainless steel can have hazardous effects on human health, especially when over-using kitchenware.