Which of the following is NOT one of the three major types of stainless steel?

The classification of stainless steel is generally based on its microstructure and composition. The three major types of stainless steel are austenitic, martensitic, and ferritic.

Austenitic stainless steels are the most common type and are known for their high corrosion resistance and excellent formability due to their face-centered cubic crystal structure.

Martensitic stainless steels are characterized by their ability to be hardened through heat treatment, offering improved strength and wear resistance, with a body-centered cubic structure.

Ferritic stainless steels are known for their good corrosion resistance and magnetic properties, featuring a body-centered cubic crystal structure as well.

Low-carbon is a term typically associated with alterations of existing types of stainless steel, specifically adjustments in carbon content to improve weldability or reduce the risk of sensitization. However, it does not classify as a distinct major type of stainless steel. Therefore, it does not fit into the primary categorization, confirming it as the correct answer to the question.