Final answer:
False. The strength of plain carbon steels increases with carbon content, and ductility decreases.
Step-by-step explanation:
The statement is False
Plain carbon steels are a type of steel alloy that contains only carbon and iron, with no other alloying elements. As the carbon content of the steel increases, the strength of the steel also increases. This is because the carbon atoms in the steel create a lattice with greater hardness and strength compared to pure iron. However, as the carbon content increases beyond a certain point, the steel becomes more brittle and less ductile. Ductility refers to the ability of a material to deform under stress without breaking. So, the ductility of plain carbon steels actually decreases with increasing carbon content.
For example, wrought iron is a type of plain carbon steel with very low carbon content (less than 0.1%). It is known for its high ductility, which makes it easy to work into various shapes. On the other hand, high carbon steel, which contains higher carbon content (up to 1.5%), is very hard but also more brittle, which makes it suitable for cutting tools but not for applications requiring high ductility.