Alloy Steel Castings

Cast alloy structural steel

According to the alloying elements, there are manganese alloy cast steel, chromium alloy cast steel and nickel-containing cast alloy steel.

Manganese alloy cast steel This type of steel uses manganese as the main alloying element, and uses silicon and molybdenum as auxiliary alloying elements. Commonly used Chinese grades are ZG30Mn, ZG40Mn, ZG40Mn2, ZG45Mn, ZG50Mn, zG50Mn2, ZG65Mn and so on. It is often used for gears, cranes and mining machinery wheels, anti-addiction parts, etc., of which the manganese content is 1.05% to 1.80%. Manganese can significantly improve the hardenability, refine the pearlite structure, improve the hardness and wear resistance, reduce the plastic-brittle transition temperature of steel, and improve the strength without reducing the plasticity. This type of steel has good weldability when the carbon content is not high. However, the solid solution strengthening effect of manganese is small, which often causes coarse grains and temper brittleness. In order to improve the strength, silicon (0.60% to 1.40%) is often added to the steel to improve the hardenability and enhance the solid solution strengthening effect. Commonly used manganese silicon steel grades in China are ZG30Mnsi, ZG35MnSi, ZG35SiMn, ZG50SiMn, ZG20MnSi, etc., which can be used as train side frames, bolsters, gears, wheels, etc. In order to reduce the temper brittleness of manganese steel, 0.15% to 0.30% molybdenum is often added. Commonly used in China are ZG20MnMo and ZG50MnMo. Diversified manganese alloy cast steels include ZG35SiMnMo, ZG35SiMnMoV, ZG42MnMoV, etc. in China. These steels can be used as excavator parts and components, large gears, and crane sleeves. Adding a small amount of chromium (0.50% to 0.80%) to manganese-silicon steel can improve hardenability, strength and wear resistance, and can produce impacted and worn castings, such as gears, linings, etc. Commonly used brands in China are ZG30CrMnSi and ZG35CrMnSi. However, this kind of steel is prone to deformation and cracking during casting and heat treatment.

Chromium alloy cast steel This type of steel uses chromium as the main alloying element, with manganese, molybdenum, nickel and other auxiliary elements. Chromium can be solid solution strengthened and significantly improve hardenability, strength and wear resistance. Commonly used unit chromium alloy cast steels in China are ZG40Cr and ZG70Cr. The former can be used for high-strength castings such as gears and wheel rims, while the latter is mainly used for wear-resistant steel castings. Chromium steel is temper brittle, and molybdenum is often added, which can further improve the strength and prevent temper brittleness. Medium carbon chromium molybdenum cast steel has good strength and wear resistance, such as ZG35CrMo can be used to make sprockets, excavator support wheels, bushings, etc. Chromium-manganese-molybdenum steel is mainly used for wear-resistant steel castings, such as ZG30CrMnMo, which can withstand large loads and is wear-resistant. Due to the formation of stable carbides, high-carbon chromium-manganese steel has high hardness and wear resistance, and can be used as casting mold steel, such as ZG5CrMnMo.

Nickel-Containing Cast Alloy Steel There are very few cast steels with nickel as the main alloy element in the low-alloy cast steel. Nickel is often combined with chromium and molybdenum to greatly improve the hardenability, and is used to make high-strength large-scale steel castings.

What Is The Difference Between High-Alloy And Low-Alloy Steels