Mechanical Engineering - Engineering Materials - Discussion

The correct answer is: martensitic stainless steel.

A steel containing 16 to 18% chromium and about 0.12% carbon is classified as martensitic stainless steel. Martensitic stainless steels are characterized by:

1. High chromium content (12-18%)
2. High carbon content (0.1-1.2%)
3. Ability to be heat-treated to form martensite, a hard, needle-like microstructure
4. Good strength, hardness, and resistance to corrosion

Here's a brief overview of the other options:

- Ferritic stainless steels: Contain 10-18% chromium, low carbon (<0.1%), and are characterized by a ferrite microstructure.
- Austenitic stainless steels: Contain 18-30% chromium, 8-20% nickel, and low carbon (<0.1%), and are characterized by an austenite microstructure.
- Nickel steel: A broad term that refers to alloys containing nickel, but not necessarily stainless steel.

=> Note that the exact classification and properties of stainless steels can vary depending on the specific composition and processing history.

Thanks @Abhi.

1. Martensitic stainless steel. The chromium steels containing 12 to 14% chromium and 0.12 to 0.35% carbon is called martensitic stainless steel, as they possess martensitic structure. These steels are magnetic and may be hardened by suitable heat treatment and the hardness obtainable depends upon the carbon content. These steels can be easily welded and machined.

2. Ferritic stainless steel. The steels containing a greater amount of chromium (from 16 to 18%) and about 0. 12% carbon are called ferritic stainless steels. These steels have better corrosion resistant property than martensitic stainless steels.

3. Austenitic stainless steel. The steel containing a high content of both chromium and nickel are called austenitic stainless steels. The most widely used steel contains 18% chromium and 8% nickel. Such a steel is commonly known as 18/8 steel. These steels are non-magnetic and possess the greatest resistance to corrosion and good mechanical properties at elevated temperature.

The Correct option is B.