The difference between casting and forging

The difference between casting and forging:


1. Casting: It is the process of smelting metal into a liquid that meets certain requirements and pouring it into a mold. After cooling, solidification, and finishing, a casting (part or blank) with a predetermined shape, size, and performance is obtained. Basic technology of modern machinery manufacturing industry.

2. The cost of casting blanks is low, and it can show its economy more for parts with complicated shapes, especially with complicated inner cavity. At the same time, it has a wide adaptability and has good comprehensive mechanical properties.

3.But the materials (such as metal, wood, fuel, modeling materials, etc.) and equipment required for casting production (such as metallurgical furnaces, sand mixers, molding machines, core making machines, sand dropping machines, shot blasting machines, cast iron flat plates, etc.) ) More, and will generate dust, harmful gases and noise to pollute the environment.

4. Casting is an early metal thermal processing technology that has been mastered by human beings, and has a history of about 6000 years. In 3200 BC, copper frog castings appeared in Mesopotamia. Between the 13th and 10th centuries BC, China had entered the heyday of bronze casting, and its craftsmanship had reached a very high level, such as the 875-kilogram sifang Wuding Ding of the Shang Dynasty, Zenghou Yizunpan of the Warring States Period, and the Western Han Dynasty.

Transmission mirrors are representative products of ancient casting. The early casting was greatly influenced by pottery. Most of the castings were tools or utensils in agricultural production, religion, life, etc., which had a strong artistic color. In 513 BC, China cast Jin Guo Zhu Ding (approximately 270 kilograms), the world’s earliest written iron found in writing. Around the 8th century, production of cast iron parts began in Europe. After the industrial revolution of the 18th century, castings entered a new period of service for large industries. In the 20th century, the development of casting was very fast. Ductile iron, malleable cast iron, ultra-low carbon stainless steel, aluminum copper, aluminum silicon, aluminum magnesium alloy, titanium-based, nickel-based alloy and other cast metal materials have been developed. New technology for inoculation of cast iron. After the 1950s, new technologies such as wet sand high pressure molding, chemically hardened sand molding and core making, negative pressure molding, and other special casting and shot blasting appeared.

5. There are many types of casting. According to the molding method, they are divided into: ① ordinary sand casting, including wet sand, dry sand and chemical hardening sand. ② Special casting, according to the molding materials, can be divided into special castings with natural mineral sand and gravel as the main molding materials (such as investment casting, mud casting, shell casting in foundry, negative pressure casting, solid casting, ceramic casting) Etc.) and special castings (such as metal casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.) with metal as the main mold material.

6. The casting process usually includes: ① the preparation of casting molds (making the liquid metal into a solid casting); casting molds can be divided into sand, metal, ceramic, clay, graphite, etc. according to the materials used, and can be divided according to the number of uses For disposable type, semi-permanent type and permanent type, the quality of casting preparation is the main factor affecting the quality of castings; ② melting and casting of casting metals, casting metals (casting alloys) mainly include cast iron, cast steel and cast nonferrous alloys; ③ Casting processing and inspection. Casting processing includes removing foreign matters from the core and casting surface, cutting out the riser, shovel and burr, and other protrusions, as well as heat treatment, shaping, rust prevention and rough processing.


1. Forging: It is a processing method that uses forging machinery to apply pressure to metal blanks to cause plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes.

2. one of the two major components of forging. Forging can eliminate metal as-looseness, weld holes, and mechanical properties of forgings are generally better than castings of the same material. For the important parts with high load and severe working conditions in the machinery, in addition to the simpler shapes that can be rolled plates, profiles or welded parts, forgings are mostly used.

3. Forging can be divided into: ① Open forging (free forging). The impact force or pressure is used to deform the metal between the upper and lower resisting irons (anvils) to obtain the required forgings. There are mainly two types of manual forging and mechanical forging. ② Closed mode forging. Metal blanks are deformed by compression in a forging die cavity with a certain shape to obtain forgings, which can be divided into die forging, cold heading, rotary forging, and extrusion. Forging according to the deformation temperature can be divided into hot forging (processing temperature is higher than the recrystallization temperature of the billet metal), warm forging (below the recrystallization temperature) and cold forging (normal temperature).

4. Forging materials are mainly carbon steel and alloy steel with various components, followed by aluminum, magnesium, titanium, copper, and their alloys. The original state of the material is bar, ingot, metal powder and liquid metal. The ratio of the cross-sectional area of ​​the metal before deformation to the die area after deformation is called the forging ratio. The correct selection of forging ratio has a lot to do with improving product quality and reducing costs.

Forging steel and cast steel are mainly forging processes of steel materials, and the processing forms are different:

Cast steel Steel used for casting. A cast alloy. Cast steel is divided into cast carbon steel, cast low alloy steel and cast special steel. Cast steel refers to a steel casting produced by the casting method. Cast steel is mainly used to manufacture parts with complex shapes that are difficult to forge or cut and require high strength and plasticity

Forged steel: Forged steel refers to various forging materials and forgings produced by the forging method. The quality of forged steel is higher than that of cast steel, and it can withstand large impact forces. The plasticity, toughness, and other mechanical properties are also higher than those of cast steel. Therefore, forged important steel parts should be used.


Commonly used mechanical parts are generally processed by casting, some automotive parts, excavator parts, pipe fittings, etc.