Main Difference – Inox vs Stainless Steel
Steel is a metal alloy composed of iron, carbon and some other elements. There are several different classifications of steel; based on the amount of carbon present in the steel, based on the other elements present in the steel, based on the applications, etc. Stainless steel is a type of steel that is best to be used in moist environments. This is because stainless steel shows a minimum or no corrosion when exposed to air with moisture unlike other forms of steel. The term inox is another name for stainless steel. Therefore there is no difference between inox and stainless steel. However, this article explains different forms and properties of stainless steel.
Key Areas Covered
1. What is Inox
– Explanation
2. What is Stainless Steel
– Definition, Properties, Different Forms
3. What is the Difference Between Inox and Stainless Steel
– Comparison of Two Terms
Key Terms: Alloy, Austenitic Stainless Steel, Carbon, Corrosion, Duplex Stainless Steel, Ferritic Stainless Steel, Inox, Iron, Martensitic Stainless Steel, Stainless Steel
What is Inox
Inox is a general term that is used to name stainless steel. A description of stainless steel is given below.
What is Stainless Steel
Stainless steel is a form of steel made by mixing molten steel with molten chromium. It is composed of about 10% of chromium along with iron and other metals and nonmetals. The other metal elements present in stainless steel are nickel, molybdenum, titanium, and copper. Non-metal additions mainly include carbon.
Chromium provides protection against rusting. Stainless steel does not undergo rusting even if it’s scratched since chromium is present all over the steel. Stainless steel has high resistant to corrosion by air under normal temperature and pressure conditions. It is even resistant to corrosion by some acids.
Since two metals are mixed together, stainless steel is very strong. But it is expensive when compared to other types of steel. In order to mix the two metals, it is essential that the metals should be in the molten state. Otherwise, a uniform mixing would not occur. Then steel is left to cool and harden. Later, the surface of the stainless steel is washed with an acid in order to remove any impurity.
Figure 1: A Barrel Made of Stainless Steel
Stainless steel can withstand high temperatures. Therefore, stainless steel is used to make kitchen items. Unlike normal steel, stainless steel has a shiny appearance which is very attractive. According to their properties, stainless steel is also divided into sub-groups as follows.
- Duplex Stainless Steel
- Martensitic Stainless Steel
- Ferritic Stainless Steel
- Austenitic Stainless Steel
Duplex stainless steel is named as such due to the presence of two phases of microstructures together. The two forms are ferritic structure and austenitic structure. The composition is roughly 50% ferritic and 50% austenitic. This makes duplex steel twice stronger than regular ferritic or austenitic.
Martensitic stainless steel is composed of about 12% chromium. Generally, this steel is tempered and hardened. The tempered form has a high toughness where the untempered form has a low toughness. This steel has a high amount of carbon than other stainless forms (up to 1.2%).
Ferritic stainless steel has a high amount of chromium and a low amount of carbon. The microstructure of ferritic stainless steel is body-centered cubic (BCC) grain structure. This structure gives this steel its magnetic properties.
Austenitic stainless steel is known as non-magnetic steel. It contains a high level of chromium and nickel along with a low amount of carbon. This form of stainless steel has face-centered cubic (FCC) crystal structure in its microstructure.
Difference Between Inox and Stainless Steel
- There is no difference between inox and stainless steel.
- Both names refer to the same chemical substance.
Conclusion
There is no difference between inox and stainless steel. Both refer to the form of steel that is composed of a high amount of added chromium in order to protect the steel from rusting. This metal alloy is very important and has many applications where rusting should not take place. There are four main types of stainless steel as duplex, ferritic, martensitic and austenitic.
References:
1. “Inox.” The Free Dictionary, Farlex, Available here.
2. Association, IMOA International Molybdenum. Duplex stainless steel. Available here.
3. “Martensitic stainless steel.” Wikipedia, Wikimedia Foundation, 24 Nov. 2017, Available here.
4. Bell, Terence. “Discover Ferritic Stainless Steel: Properties, Types and Applications.” The Balance, Available here.
Image Courtesy:
1. “Barrique inox” By Olivier Colas – Own work (CC BY-SA 4.0) via Commons Wikimedia
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