What are the advantages of alloy steel compared with similar carbon steel?

In addition to the iron and carbon of ordinary carbon steel, alloy steel is also added with other alloying elements according to performance requirements, such as common chromium, nickel, molybdenum, manganese, silicon, etc., in order to improve heat treatment performance, mechanical properties, etc., usually the price Higher than ordinary carbon steel.
Ordinary low alloy steel has the following advantages over similar carbon steel:
1: High strength, good plasticity and toughness. Due to the effect of alloying elements, its strength is 25%-50% higher than that of ordinary carbon steel, its elongation is 15%-23%, and its impact toughness at room temperature is higher than 60J/cm^2.
2: Good weldability. Due to the low carbon content and low alloy element content, it has good plasticity and low hardenability, so it is not suitable for quenched structures or cracks to appear at the weld.
3: Good cold and hot pressure processing performance. Because of its good plasticity and small deformation resistance, it is not easy to crack after pressure processing.
4: Good corrosion resistance. It has higher corrosion resistance than carbon steel under various atmospheric conditions.