What is the difference between steel & stainless steel?

Used materials in the world. About 1.3 billion tons is produced each year. The boom in India and China has caused a massive increase in the demand for steel in recent years. It is used in architectural fabrications, economic and a lot more.

Steel is an alloy of iron and other elements, primarily carbon. There are many sub-categories of steel with different alloys for different uses. The properties that vary the most between steel types are hardness, strength, ductility, aesthetics and cost. It is one of the world's most recycled materials, with a recycling rate of more than 60% globally.

Stainless steel differs from carbon steel by the amount of chromium present. It is an alloy with a minimum of 10.5 % chromium content. The chromium produces a thin layer of oxide on the surface of the steel known as the 'passive layer'. This layer is too thin to be visible, so the metal retains its lustre. Also, when the surface of the metal is scratched, this layer quickly reforms. It is impervious to water and air, so protects the metal beneath, preventing any further corrosion of the surface. Increasing the amount of chromium gives stainless steel increased resistance to corrosion.

Stainless steel does not stain, corrode or rust as easily as ordinary steel although it is not totally stain-proof. It is also known as corrosion resistant steel when the grade and alloy type are not detailed, particularly in the aviation industry. Different grades and surface finishes of stainless steel are available to suit the environment in which the material will be used. Nickel, titanium, copper and molybdenum may be added for useful properties such as increased corrosion resistance, appearance and enhanced formability.