I. Casting 1, Casting: is the metal melting into a certain required liquid and poured into the mold, after cooling solidification, scrubbed treatment of the predetermined shape, size and performance of the casting (parts or blanks) of the process.

    The basic technology of modern machinery manufacturing industry.

    2, the blank cost of casting production is low, for the shape is complex, especially has the complex cavity of parts, can show its economy, at the same time it is more adaptable, and has good comprehensive mechanical properties.

    3, but the material required for casting production (such as metal, wood, fuel, modelling materials, etc.) and equipment (such as metallurgical furnaces, sand mixer, molding machine, core-making machine, sand-blasting machine, shot blasting machine, cast iron plate, etc.) more, and will produce dust, harmful gases and noise and pollute the environment. 4. Casting is a kind of metal thermal processing technology, which has a history of about 6,000 years. In 3200 BC, Bronze Frog castings appeared in Mesopotamia. Between 10th century BC 13 to BC, China has entered the heyday of bronze castings, the process has reached a very high level, such as the Shang Dynasty heavy 875 kilograms ban, the Warring States Marquis Yi and the Western Han Dynasty light mirror, etc. are the representative products of ancient foundry. The early casting was influenced by pottery, most of the castings were agricultural production, religion, life and other tools or utensils, the artistic color is thicker. 513 BC, China cast the world's first in the word recorded iron castings-jin Ding (about 270 kilograms heavy). Before and after 8th century A.D., the production of iron castings in Europe began. After the Industrial revolution of 18th century, castings entered a new period of service for large industries. Into the 20th century, casting the rapid development, has developed ductile iron, malleable iron, ultra-low carbon stainless steel, as well as aluminum, aluminum, aluminum, magnesium alloy, titanium, nickel base alloy and other casting metal materials, and invented the new process of inoculation of gray iron.

    Since the 50 's, there has been a high-pressure molding of wet sand, chemical hardening sand molding and core-making, negative pressure molding and other special casting, shot blasting cleaning and other new processes. 5, casting a lot of types, according to the habit of modelling methods are divided into: ① ordinary sand casting, including wet sand type, dry sand type and chemical hardening sand type 3 categories. ② Special casting, according to molding materials can be divided into natural mineral sand and gravel as the main molding materials of special casting (such as investment casting, clay casting, casting workshop shell mold casting, negative pressure casting, solid casting, ceramic casting, etc. and special casting with metal as main casting material (such as metal casting, pressure casting, continuous casting, low pressure casting)

    , centrifugal casting, etc.) two categories. 6. Casting process usually includes: ① mold (make liquid metal into solid casting container) preparation, mold according to the material can be divided into sand, metal, ceramic, clay, graphite, etc., according to the number of times can be divided into one-off, semi-permanent and permanent type, mold preparation is the main factor affecting the quality of castings; ② Melting and pouring of casting metals, casting metal (casting alloy) are cast iron, cast steel and cast non-ferrous alloy; ③ castings treatment and inspection, casting treatment includes the removal of core and casting surface foreign bodies, the removal of sprue, shovel grinding burr and the drape and so on, heat treatment, plastic, rust treatment and roughing and so on.

Import Pump Valve

    Ii. Forging

    1, forging: the use of forging machinery to the metal billet pressure, so that it produces plastic deformation to obtain a certain mechanical properties, a certain shape and size forgings processing methods. 2. One of the two major parts of forging. Through forging can eliminate the cast loose metal, weld hole, the mechanical properties of forgings are generally better than the same material castings.

    Machinery in the high load, critical working conditions of the important parts, in addition to a simpler shape can be rolled plate, profiles or welding parts, more use of forgings. 3, forging according to the forming method can be divided into: ① open-type forging. The use of impact or pressure to make the metal in the upper and lower two iron (anvil block) between the deformation to obtain the required forgings, mainly manual forging and mechanical forging two. ② closed mode forging. Metal blanks in a certain shape of the forging die in the compression deformation and obtain forgings, can be divided into die forging, heading, rotating forging, extrusion and so on.

    According to the deformation temperature forging can be divided into hot forging (processing temperature is higher than the billet metal recrystallization temperature), warm forging (below recrystallization temperature) and cold (room temperature). 4, forging materials are mainly various components of carbon steel and alloy steel, followed by aluminum, magnesium, titanium, copper and other alloys. The original state of the material is bar, ingot, metal powder and liquid metal. The ratio between the transverse area of metal before deformation and the die area after deformation is called the forging ratio.

The correct choice of forging ratio is very important to improve product quality and reduce cost.

    Iii. identification of castings and forgings

    1. The fine density of the surface microstructure of forgings, the surface of castings should be thicker, and the machined surface of forgings should be brighter.

    2, Cast iron section hair dark color, and forged steel section silver.

    3, listen to sound, forgings Compact, after the blow sound crisp, casting sound dull. 4, grinding with a grinder to see the two sparks with different (forging light) and so on.