Home
About Us
Company Profile
Production Equipment
Testing Equipment
Honors and Qualifications
Partners
Products
Cast Steel
Cast Iron
Application
Construction Machinery
Water Valve
Railways and Rail Transit
Machine Tool
Blog
Company News
Industry News
Contact Us
Contact Information
Online Message
2025.05.28
What are the characteristics of cast steel?
Offers maximum freedom in the choice of casting shape and size, enabling the production of parts with complex shapes and hollow sections. Finished products can be quickly made from drawings, shortening delivery times.
2025.05.21
Introduction to Cast Steel Classification
Cast steel is a cast alloy, mainly composed of iron and carbon, with a carbon content between 0-2%, and is a steel material specifically used for manufacturing steel castings.
2025.05.14
How to improve the fluidity of cast steel?
Improving the fluidity of cast steel requires a multi-faceted approach, including optimizing chemical composition, improving smelting processes, adjusting casting processes, and optimizing mold design.
2025.04.27
Classification of Cast Iron
Except for a small amount dissolved in ferrite, the remaining carbon in cast iron exists in the form of cementite. Its fracture is silvery white, hence the name white cast iron. Currently, white cast iron is mainly used as a raw material for steelmaking and as a blank for producing malleable cast iron.
The difference between cast steel and cast iron
The essential difference between cast iron and cast steel lies in their different chemical compositions. In engineering, it is generally considered that if the carbon content is higher than 2%, it is iron; otherwise, it is steel. Due to the different compositions, their microstructure and properties also differ. Generally speaking, cast steel has better plasticity and toughness, exhibiting good elongation, reduction of area, and impact toughness, while cast iron is characterized by its hardness and brittleness. Cast iron can be classified into: ① Gray cast iron. It has a higher carbon content (2.7%～4.0%), with carbon mainly existing in the form of flake graphite. The fracture surface is gray, hence the name gray iron. It has a low melting point (1145～1250℃), small shrinkage during solidification, compressive strength and hardness close to carbon steel, and good damping capacity. It is used to manufacture machine tool beds, cylinders, housings, and other structural parts. ② White cast iron. It has a lower carbon and silicon content, with carbon mainly existing in the form of cementite. The fracture surface is silvery white. It has large shrinkage during solidification, easily producing shrinkage cavities and cracks. It has high hardness and high brittleness and cannot withstand impact loads. It is often used as blanks for malleable cast iron and for manufacturing wear-resistant parts. ③ Malleable cast iron. It is obtained by annealing white cast iron, with graphite distributed in a nodular form, also known as ductile iron. It has a uniform microstructure, good wear resistance, and good plasticity and toughness. It is used to manufacture parts with complex shapes that can withstand strong dynamic loads. ④ Ductile iron. It is obtained by spheroidizing the molten iron of gray cast iron, with graphite precipitated in a spherical form, also known as ductile cast iron. It has higher strength, better toughness, and plasticity than ordinary gray cast iron. It is used to manufacture internal combustion engines, automotive parts, and agricultural machinery. ⑤ Vermicular cast iron. It is obtained by vermicularizing the molten iron of gray cast iron, with graphite precipitated in a vermicular form. Its mechanical properties are similar to ductile iron, and its casting properties are between gray cast iron and ductile iron. It is used to manufacture automotive parts. ⑥ Alloy cast iron. It is obtained by adding an appropriate amount of alloying elements (such as silicon, manganese, phosphorus, nickel, chromium, molybdenum, copper, aluminum, boron, vanadium, tin, etc.) to ordinary cast iron. Alloying elements change the matrix microstructure of cast iron, thus exhibiting corresponding heat resistance, wear resistance, corrosion resistance, low-temperature resistance, or non-magnetic properties. It is used to manufacture parts for mining, chemical machinery, and instruments. Cast Steel Cast steel is steel used for casting castings. It is a type of casting alloy. Cast steel is divided into three categories: cast carbon steel, cast low-alloy steel, and cast special steel. ① Cast carbon steel. Cast steel with carbon as the main alloying element and containing a small amount of other elements. Cast steel with less than 0.2% carbon is called cast low-carbon steel; cast steel with 0.2%～0.5% carbon is called cast medium-carbon steel; and cast steel with more than 0.5% carbon is called cast high-carbon steel. With the increase in carbon content, the strength and hardness of cast carbon steel increase. Cast carbon steel has high strength, plasticity, and toughness, and is relatively low in cost. In heavy machinery, it is used to manufacture parts that bear large loads, such as rolling mill housings and hydraulic press bases; in railway vehicles, it is used to manufacture parts that bear large loads and impact, such as bolster, side frame, wheels, and couplers. ② Cast low-alloy steel. Cast steel containing alloying elements such as manganese, chromium, and copper. The total amount of alloying elements is generally less than 5%, and it has high impact toughness and can obtain better mechanical properties through heat treatment. Cast low-alloy steel has better performance than carbon steel, can reduce the weight of parts, and improve service life. ③ Cast special steel. Alloy cast steel produced to meet special needs. There are many varieties, usually containing one or more high-content alloying elements to obtain certain special properties. For example, high-manganese steel containing 11%～14% manganese is resistant to impact wear and is often used for wear-resistant parts of mining machinery and construction machinery; various stainless steels with chromium or chromium-nickel as the main alloying elements are used for parts working under corrosive conditions or at temperatures above 650℃, such as valve bodies, pumps, containers used in the chemical industry, or turbine casings of large-capacity power plants. Although both are iron-carbon alloys, due to the different percentages of carbon, silicon, manganese, phosphorus, sulfur, and other chemical elements they contain, they have different metallographic structures after crystallization, exhibiting many differences in mechanical and process properties. For example, in the as-cast state, the elongation, reduction of area, and impact toughness of cast iron are lower than those of cast steel; the compressive strength and damping capacity of cast iron are better than those of cast steel; the fluidity of gray cast iron is better than that of cast steel, making it more suitable for casting thin-walled castings with complex structures; in bending tests, cast iron undergoes brittle fracture, while cast steel undergoes bending deformation, etc. Therefore, they are suitable for casting parts with different requirements. How to distinguish cast iron and cast steel in actual production and life: 1. Brightness. Cast steel is bright, while cast iron is dark and gray. Gray iron and ductile iron in cast iron are different, with ductile iron being brighter than gray iron. 2. Grains. Cast steel is very dense, and grains are generally invisible to the naked eye. Grains can be seen in gray iron and ductile iron, with gray iron having larger grains. 3. Sound. The sound of cast steel colliding is "crisp", different from that of cast iron. 4. Gas cutting. The surface of cast steel is rough, and the riser and pouring basin areas are large, requiring gas cutting to remove them. Ductile cast iron cannot be cut by gas cutting. 5. Toughness. The toughness of cast steel is close to that of steel plate, the toughness of ductile cast iron is slightly lower, and thin-walled parts can achieve 20-30 degrees of bending, while gray cast iron has no toughness. 6. Difference between malleable iron and ductile iron. The hardness, wear resistance, and tensile strength of ductile iron are much greater than those of malleable iron, with a tensile strength of up to 1000 MPa. Ductile iron can be used to make engine crankshafts, gears, and various high-strength structural parts. Malleable iron and ductile iron can be distinguished by listening to their sounds. Malleable iron has a sharp and short sound, while ductile iron has a loud and long echo. Although both are iron-carbon alloys, due to the different percentages of carbon, silicon, manganese, phosphorus, sulfur, and other chemical elements they contain, they have different metallographic structures after crystallization, exhibiting many differences in mechanical and process properties. For example, in the as-cast state, the elongation, reduction of area, and impact toughness of cast iron are lower than those of cast steel; the compressive strength and damping capacity of cast iron are better than those of cast steel. The fluidity of gray cast iron is better than that of cast steel, making it more suitable for casting thin-walled castings with complex structures. In bending tests, cast iron undergoes brittle fracture, while cast steel undergoes bending deformation, etc. Therefore, they are suitable for casting parts with different requirements.
The production process of cast steel
Suitable scrap steel is selected as the main raw material, requiring clear sources, relatively stable composition, and no excessive impurities or oil stains, etc. Different types of scrap steel may require different process adjustments in subsequent processing to ensure the quality of the molten steel.
