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What are the differences between forging valves and casting valves?
Release date：2018/9/22
Castings are made by integral casting of materials in a mold. The stress distribution is uniform and there is no restriction on the direction of compression. The forging is formed by the force in the same direction. The stress in the forging is directional and can only bear directional pressure.
First, casting
1. Casting: It is the process of melting metal into a liquid which meets certain requirements and pouring it into the mold. After cooling, solidifying and cleaning, the castings (parts or blanks) with predetermined shapes, sizes and properties can be obtained. The basic technology of modern machinery manufacturing industry.
2. The cost of casting blank is low, and it is more economical for the parts with complex shape, especially for the parts with complex inner cavity. At the same time, it has wide adaptability and better comprehensive mechanical properties.
3. However, there are many materials (such as metals, wood, fuel, molding materials, etc.) and equipment (such as metallurgical furnace, sand mixer, molding machine, core-making machine, sand-dropping machine, shot blasting machine, cast iron plate, etc.) needed for casting production, and they will produce dust, harmful gases and noise and pollute the environment.
4, casting is an early metal thermal processing technology, which has been around for 6000 years. In 3200 BC, a bronze frog was found in Mesopotamia. From the 13th century BC to the 10th century BC, China has entered the heyday of bronze castings, and the technology has reached a fairly high level, such as the 875 kg Smu Wufangding Ding of the Shang Dynasty, Zeng Hou Yizun Pan of the Warring States and the light transmission mirror of the Western Han Dynasty, which are the representative products of ancient casting. Earlier foundries were greatly influenced by pottery. Most of the castings were tools or utensils for agricultural production, religion, life and other aspects, with strong artistic color. In 513 B.C., China produced the world's earliest written cast iron castings - Jin tripod (about 270 kg). Around eighth Century, Europe began to produce iron castings. After the industrial revolution in eighteenth Century, castings entered a new era of service for large industries. Get into
In the 20th century, casting developed rapidly. Nodular cast iron, malleable cast iron, ultra-low carbon stainless steel, aluminum-copper, aluminum-silicon, aluminum-magnesium alloy, titanium-based, nickel-based alloy and other casting metal materials were developed successively. Since the 1950s, new technologies such as high-pressure moulding with wet sand, chemical hardened sand moulding and coring, negative pressure moulding and other special casting and shot blasting cleaning have emerged.
5. There are many kinds of foundry. According to the moulding method, it is customarily divided into: 1. Ordinary sand mold, including green sand mold, dry sand mold and chemical hardening sand mold. (2) Special casting can be divided into special casting (such as investment casting, clay casting, shell casting, negative pressure casting, solid casting, ceramic casting) and special casting (such as metal casting, pressure casting) with natural mineral sand and stone as the main molding materials. Manufacturing, continuous casting, low pressure casting, centrifugal casting, etc.) two kinds.
6. Casting technology usually includes: (1) preparation of casting mold (which makes liquid metal a container for solid casting). The casting mold can be divided into sand mold, metal mold, ceramic mold, mud mold and graphite mold according to the materials used. The casting mold can be divided into disposable mold, semi-permanent mold and permanent mold according to the usage times. The quality of casting is mainly affected by the quality of casting. Major factors; (2) Melting and pouring of casting metals, casting metals (casting alloys) mainly cast iron, cast steel and cast non-ferrous alloys; (3) Casting treatment and inspection, casting treatment including removal of core and casting surface foreign bodies, removal of gating and riser, burr shoveling and cloak and other protrusions as well as heat treatment, shaping, anti-rust treatment. And rough machining.
Two. Forging
1. Forging: It is a method of applying pressure on metal billet by forging machine to produce plastic deformation so as to obtain forgings with certain mechanical properties, shapes and sizes.
2. One of the two components of forging and pressing. The mechanical properties of forgings are generally superior to those of castings of the same material. In machinery, the important parts with high load and severe working conditions are usually forged, except the rolled sheets, profiles or welded parts with simple shapes.
3, forging according to the forming method can be divided into: 1. Open forging (free forging). There are mainly two kinds of forgings, manual forging and mechanical forging, in which the metal is deformed between the upper and lower iron blocks by means of impact force or pressure. 2. Closed die forging. The metal blank is compressed and deformed in a certain shape forging die chamber, which can be divided into die forging, cold upsetting, rotary forging, extrusion and so on. Forging can be divided into hot forging (processing temperature is higher than recrystallization temperature of billet metal), warm forging (lower than recrystallization temperature) and cold forging (normal temperature).
4. Forging materials are mainly carbon steel and alloy steel of various components, followed by aluminum, magnesium, titanium, copper and other alloys. The raw materials are bar, ingot, metal powder and liquid metal. The ratio of cross sectional area before deformation to the area of the die after deformation is called forging ratio. The correct selection of forging ratio has great relationship with improving product quality and reducing cost.
Three. Identification of castings and forgings.
1. The surface structure of the forging should be fine and the surface of the casting should be thicker, while the surface of the forging should be brighter.
2. The cast iron section is grey and dark, while the forged steel section is bright.
3, listen to the sound, forgings are compact, blow after the sound is crisp, casting sound dull.
4. Use the grinder to polish the sparks and see the sparks of them.
First, casting
1. Casting: It is the process of melting metal into a liquid which meets certain requirements and pouring it into the mold. After cooling, solidifying and cleaning, the castings (parts or blanks) with predetermined shapes, sizes and properties can be obtained. The basic technology of modern machinery manufacturing industry.
2. The cost of casting blank is low, and it is more economical for the parts with complex shape, especially for the parts with complex inner cavity. At the same time, it has wide adaptability and better comprehensive mechanical properties.
3. However, there are many materials (such as metals, wood, fuel, molding materials, etc.) and equipment (such as metallurgical furnace, sand mixer, molding machine, core-making machine, sand-dropping machine, shot blasting machine, cast iron plate, etc.) needed for casting production, and they will produce dust, harmful gases and noise and pollute the environment.
4, casting is an early metal thermal processing technology, which has been around for 6000 years. In 3200 BC, a bronze frog was found in Mesopotamia. From the 13th century BC to the 10th century BC, China has entered the heyday of bronze castings, and the technology has reached a fairly high level, such as the 875 kg Smu Wufangding Ding of the Shang Dynasty, Zeng Hou Yizun Pan of the Warring States and the light transmission mirror of the Western Han Dynasty, which are the representative products of ancient casting. Earlier foundries were greatly influenced by pottery. Most of the castings were tools or utensils for agricultural production, religion, life and other aspects, with strong artistic color. In 513 B.C., China produced the world's earliest written cast iron castings - Jin tripod (about 270 kg). Around eighth Century, Europe began to produce iron castings. After the industrial revolution in eighteenth Century, castings entered a new era of service for large industries. Get into
In the 20th century, casting developed rapidly. Nodular cast iron, malleable cast iron, ultra-low carbon stainless steel, aluminum-copper, aluminum-silicon, aluminum-magnesium alloy, titanium-based, nickel-based alloy and other casting metal materials were developed successively. Since the 1950s, new technologies such as high-pressure moulding with wet sand, chemical hardened sand moulding and coring, negative pressure moulding and other special casting and shot blasting cleaning have emerged.
5. There are many kinds of foundry. According to the moulding method, it is customarily divided into: 1. Ordinary sand mold, including green sand mold, dry sand mold and chemical hardening sand mold. (2) Special casting can be divided into special casting (such as investment casting, clay casting, shell casting, negative pressure casting, solid casting, ceramic casting) and special casting (such as metal casting, pressure casting) with natural mineral sand and stone as the main molding materials. Manufacturing, continuous casting, low pressure casting, centrifugal casting, etc.) two kinds.
6. Casting technology usually includes: (1) preparation of casting mold (which makes liquid metal a container for solid casting). The casting mold can be divided into sand mold, metal mold, ceramic mold, mud mold and graphite mold according to the materials used. The casting mold can be divided into disposable mold, semi-permanent mold and permanent mold according to the usage times. The quality of casting is mainly affected by the quality of casting. Major factors; (2) Melting and pouring of casting metals, casting metals (casting alloys) mainly cast iron, cast steel and cast non-ferrous alloys; (3) Casting treatment and inspection, casting treatment including removal of core and casting surface foreign bodies, removal of gating and riser, burr shoveling and cloak and other protrusions as well as heat treatment, shaping, anti-rust treatment. And rough machining.
Two. Forging
1. Forging: It is a method of applying pressure on metal billet by forging machine to produce plastic deformation so as to obtain forgings with certain mechanical properties, shapes and sizes.
2. One of the two components of forging and pressing. The mechanical properties of forgings are generally superior to those of castings of the same material. In machinery, the important parts with high load and severe working conditions are usually forged, except the rolled sheets, profiles or welded parts with simple shapes.
3, forging according to the forming method can be divided into: 1. Open forging (free forging). There are mainly two kinds of forgings, manual forging and mechanical forging, in which the metal is deformed between the upper and lower iron blocks by means of impact force or pressure. 2. Closed die forging. The metal blank is compressed and deformed in a certain shape forging die chamber, which can be divided into die forging, cold upsetting, rotary forging, extrusion and so on. Forging can be divided into hot forging (processing temperature is higher than recrystallization temperature of billet metal), warm forging (lower than recrystallization temperature) and cold forging (normal temperature).
4. Forging materials are mainly carbon steel and alloy steel of various components, followed by aluminum, magnesium, titanium, copper and other alloys. The raw materials are bar, ingot, metal powder and liquid metal. The ratio of cross sectional area before deformation to the area of the die after deformation is called forging ratio. The correct selection of forging ratio has great relationship with improving product quality and reducing cost.
Three. Identification of castings and forgings.
1. The surface structure of the forging should be fine and the surface of the casting should be thicker, while the surface of the forging should be brighter.
2. The cast iron section is grey and dark, while the forged steel section is bright.
3, listen to the sound, forgings are compact, blow after the sound is crisp, casting sound dull.
4. Use the grinder to polish the sparks and see the sparks of them.
