Material Procurement

Cast iron materials refer to iron-carbon alloys with carbon content more than 2.11%. In addition to carbon, there are also elements such as silicon, manganese, and a small amount of sulfur and phosphorus. Cast iron is usually made of pig iron, scrap steel, ferroalloys, etc. in different proportions through smelting. It has good performance in features such as casting, shock absorbing, pressure resistance, wear resistance, cutting processing, etc. Compared with other metal materials, cast iron production equipment and technology are relatively simple and low in price, so it is widely used in machinery manufacturing, petroleum, chemical industry, metallurgy, transportation and military industries, etc. Industrial cast iron generally contains 2.5% to 3.5% carbon. Carbon mostly presents in the form of graphite in cast iron. Based on the form of graphite, it can be roughly divided into white cast iron (steel-making pig iron), gray cast iron, malleable cast iron, ductile iron, etc.

Aluminum alloy is the general term for aluminum-based alloys. The main alloy elements are copper, silicon, magnesium, zinc, and manganese, and the secondary alloy elements are nickel, iron, titanium, and chromium. The content of aluminum on the earth is only next to oxygen and silicon, and its density is only one-third of iron. It is the fourth most conductive metal after gold, silver, and copper. Aluminum alloy has low density but relatively high strength, which is close to or excessive to high-quality steel. It has good plasticity and can be processed into various profiles, with excellent electrical conductivity and thermal conductivity. It is widely used in industry and its usage is only second to steel.

Stainless steel, also known as galvanized iron, is the common name for corrosion-resistant steel. More specifically, steel with chromium (Cr) content greater than 12% in molten steel is called stainless steel. Stainless steel is usually made of iron as the basic material and added 12% to 30% chromium and other alloying elements into a high alloy steel. Its chemical composition is based on iron, carbon, chromium, and other alloying elements such as nickel, molybdenum, copper, titanium, niobium, etc. Chromium is the most important alloying element of stainless steel, which can strengthen the corrosion resistance, especially the lower the carbon content, the better the corrosion resistance. Stainless steel can work safely for a long time at a temperature of -196°C to 800°C, without releasing harmful substances, and keep the material performance stable. Therefore, the stainless steel material is safe and non-toxic, free from corrosion and exudation, and meets the requirements of safety and hygiene.

Carbon steel is an iron alloy with carbon elements, that is, iron-carbon alloy. Carbon steel refers to carbon content higher than 0.02% and lower than 2% (above 2% is called cast iron, and less than 0.02% is called wrought iron). It is the material with the highest production and few other elements mixed. Carbon steel has the characteristic of close-connected carbon bonds, and it is stronger than iron, harder than stainless steel, and cheaper. Carbon steel is divided into high carbon steel, medium carbon steel, and low carbon steel. It is usually used on metal parts that require strength, hardness, and wear resistance. The more content of carbon in steel, the higher its hardness, strength, and wear resistance after heat treatment.