Alloy steel has higher strength and toughness than carbon steel, and its strengthening effect tends to be obvious with the increase of the degree of unbalanced structure. The strength of annealed alloy steel is not much superior to that of carbon steel. In the normalized state, the strength of alloy steel is significantly higher than that of carbon steel. After quenching and tempering, the strengthening effect of alloy steel is the most significant.

The hardenability of alloy steel mainly depends on the carbon content, which is slightly higher than that of carbon steel with the same carbon content, but the hardenability and tempering stability of alloy steel are significantly improved, so alloy steel is suitable for manufacturing cross-sections in stainless steel engineering Large size, requires a thicker hardened layer, or requires steel with high strength, hardness, plasticity and toughness, and the cooling rate of alloy steel is slower than that of carbon steel during quenching, and it is not easy to deform and crack. Small parts are particularly advantageous.

Some alloy steels also have good hot hardness and other special properties, such as heat resistance, corrosion resistance, wear resistance and magnetic properties.

The forming process and heat treatment process are also complex, so carbon steel should be preferred under the premise of meeting the requirements of use. However, for stainless steel parts with large size and complex shape, which require high strengthening performance and high precision, or require hot hardness and other For parts with special properties, alloy steel should still be used.