minor elements Cr Al Cu Ti effects on steel
In structural steel and tool steel, chromium can significantly improve the strength, hardness and wear resistance, so that the steel has good oxidation resistance and corrosion resistance, so it is an important alloy element of stainless steel and heat-resistant steel; it can also improve steel The hardenability is a very important alloy element. But chromium will also increase the brittleness transition temperature of steel and increase the temper brittleness of steel, which will cause unnecessary troubles for the processing process. Chrome were added in steel in the form of ferro chrome, FeCr in short. It’s a regular ferro-alloy.
Copper is a common metal. It is often used alone in industrial manufacturing. In steel, copper can improve strength and toughness, especially atmospheric corrosion properties. The disadvantage is that it is prone to hot brittleness during hot working, and the plasticity is significantly reduced when the copper content exceeds 0.5%. When the copper content is less than 0.50%, it has no effect on weldability.
Aluminum is a commonly used deoxidizer in steel. Adding a small amount of aluminum to the steel can refine the grains and improve the impact toughness, such as 08Al steel for deep drawing sheet. Aluminum also has oxidation resistance and corrosion resistance. The combination of aluminum and chromium and silicon can significantly improve the high-temperature non-skinning performance and high-temperature corrosion resistance of steel. The disadvantage of aluminum is that it affects the hot workability, welding performance and cutting performance of steel.
Titanium is a strong deoxidizer in steel. It can make the internal structure of steel compact, refine grain strength; reduce aging sensitivity and cold brittleness. Improve welding performance. Adding proper titanium to Cr18Ni9 austenitic stainless steel can avoid intergranular corrosion. Ferrotitanium was the main form when Ti added into steel.