Steel containing less than 0.15% carbon content is known as-

Explanation

Explanation: Low Carbon Steel (Mild Steel): Low carbon steel is an alloy of iron and carbon. The carbon content varies from 0.05 to 0.15 % for dead mild steel and 0.15 to 0.3 % for mild steel. The dead mild steel is very much ductile and is used for making various components like sheets, strips, wires, rods etc. The mild steel is soft and ductile. It is used for making various structural sections like angles, channels, beams, rods, pins, etc. Medium carbon steel: For medium carbon steel, the carbon percentage varies from 0.3 to 0.8%. These steels have better strength and not very easy to shape as mild steel. The hardness is slightly higher, and ductility is poor. The machine parts requiring strength like springs, automobile parts, shafts, dies for forging etc. are made from medium carbon steel. High Carbon steel: The carbon percentage varies from 0.8 to 1.5. A high percentage of carbon gives hardness and strength to the metal. It is mainly used for tools like chisels, hammers, dies, punches, broaches, reamers, drills, taps, etc. and the machine parts like springs, mandrels and similar parts requiring high strength and hardness. High-speed steel (HSS): This is high alloy steel which can be used to cut metal at a cutting speed of 2 to 3 times that of high carbon steel. The most commonly used HSS has a composition called 18 – 4 – 1 i.e. tungsten 18%, chromium 4%, vanadium 1%. The HSS is used for cutting tools in lathes, shapers, planers, milling machines, drilling machines, broaching machines etc.