Which option correctly identifies one of the three major steel groups?

• A. Carbon steels
• B. Low-alloy steels
• C. Alloy steels
• D. Stainless steels

Answer: (A)

Carbon steels are one of the three broad steel families used in welding practice. In this classification, the major groups are carbon steels, alloy steels, and stainless steels. Carbon steels are defined by having carbon as the primary alloying element, with other elements kept to a minimum. Their properties—strength and hardness—mostly come from the amount of carbon present, and they typically lack inherent corrosion resistance unless protected by coatings or environments. This makes carbon steels the foundational group in many structural and fabrication applications. The other two major families are alloy steels, which include steels with significant alloying elements to tailor strength and other properties, and stainless steels, which contain chromium (and often other elements) to resist corrosion. Low-alloy steels are a subset within alloy steels, so they aren’t identification of a separate major group.