What role does manganese play in steel properties

Manganese (Mn) is added to steel as an element for deoxidation and sulfur removal, and is a beneficial element in steel.

Manganese has strong deoxidation and desulfurization ability, and it can combine with sulfur to form MnS, thereby eliminating the harmful effects of sulfur to a considerable extent and significantly improving the hot workability of steel.

At the same time, manganese has a good influence on the mechanical properties of carbon steel, and it can improve the hardness, strength and wear resistance of steel. The manganese content is less than 0.8%, which can greatly improve the yield limit and strength limit of carbon steel while maintaining (or only slightly reducing) the original plasticity and impact toughness.

Manganese also has an effect on the weldability of steel. When the manganese content is very low, manganese mainly plays the role of eliminating hot brittleness. At this time, the influence of manganese on welding performance, especially when the sulfur content is slightly higher, is beneficial; but when the manganese content is far more than the elimination of hot brittleness at the necessary content, the excess manganese will significantly increase the supercooling ability of the austenite. At this time, manganese mainly plays the role of increasing the formation of cold cracks, which will make the weldability of the steel worse.