Large forgings are pieces of metal that have undergone pressure-induced plastic deformation to take on the desired shape or adequate compression force. Typically, pressure or the use of a hammer are used to develop strength. The metal's physical characteristics are enhanced and its grain structure is polished during the casting process.
Large forgings are defined as free forgings produced by hydraulic presses of more than 1,000 tons and free forging hammers of more than 5 tons, as well as hot die forging equipment of more than 6,000 tons and die forging hammers of more than 10 tons, by the China Forging Association. Forgings. The items are typically highly customized, involve complex procedures, and have high overall performance criteria. They are mostly employed in the production of vital and crucial parts for large machinery, such as the main shafts and rotors of steam turbines, maritime forgings, and metallurgical rolls.
Ring components, big free forgings, large die forgings, and large diameter thick wall seamless pipe fittings are the four categories under which large forgings fall. Large free forgings are those made with a free forging hydraulic press that weighs more than 1,000 tons or a free forging hammer that weighs more than 3 tons. Large die forgings are those created by die forging presses with a tonnage of over 6,000, hydraulic presses with a tonnage over 8,000, or die forging hammers with a tonnage above 10. Large forgings are technically challenging to make and have stringent internal quality standards.
A number of processing processes are used in the forging production process, which is concentrated on the shaping and deformation of forgings.
1. The two basic operations before forging are blanking and heating. The initial blank is created using the blanking process to the standards and measurements needed for forging. The procedure should heat the original blank in accordance with the heating temperature and production rhythm required for forging deformation in addition to eliminating rust, surface flaws, and anti-oxidation lubrication when necessary.
2. To meet the fundamental internal and exterior quality requirements of the forging, the blank is plastically deformed using a variety of forging tools. There may be several steps in this process.
3. The forging's cooling process begins right after forging deformation and continues until forging deformation is complete. Second, a number of procedures such cutting, forging, heat treating, correction, and surface cleaning must be carried out in order to make up for the shortcomings in the earlier operations and ensure that the forgings fully satisfy the criteria of the forging product drawings. The cooling and heat treatment operations of forgings are occasionally closely integrated in order to achieve certain structural qualities.
Before forgings leave the factory and in between each procedure, quality inspection is required. According to the specifications of semi-finished goods and forgings, comprehensive shape and size, surface quality, metallographic structure, mechanical properties, and other testing items can be determined.
Aluminum alloy forging temperature range and heating specifications
Starting from improving plasticity and reducing deformation resistance, we hope to increase the heating temperature of metal as much as possible; but in order to ensure product quality and avoid heating defects, it is not good for the heating temperature to be too high. In order to reduce fires, save energy, and improve labor productivity, not only the heating temperature is desired to be high, but also the temperature at the end of forging is low; however, in order to avoid forging cracks caused by severe work hardening, the forging temperature should not be too low. Therefore, these factors are contradictory and limiting, and the forging temperature range of aluminum alloy forgings must be fully considered.
Basic guidelines for calculating the forging temperature range for an aluminum alloy The forging temperature range is the temperature range between the metal forging start temperature and the forging end temperature.
Basic principles for determining forging temperature range:
1. Ensure that the metal has good plasticity and low deformation resistance within the forging temperature range. 2. Ensure that the forgings are of good quality. 3. Try to expand the forging temperature range as much as possible to reduce the number of fires, save energy and improve forging productivity.
In order to properly apply the aforementioned concepts, we must first create the notion of quality. This requires ensuring good blank heating, good plasticity in aluminum alloy forgings, a reduction in heating fires, an increase in labor productivity, and a reduction in heat energy loss.
Develop metal heating specifications
The relationship between the furnace temperature or material temperature changing with time is specified at each stage of metal heating in order to accomplish the goals of high quality, high production, and low consumption. This is known as the heating specification. The term "blank temperature" refers to the control of furnace temperature, and it varies over time. The heating specification makes use of a temperature change curve for user-friendliness, often a furnace temperature change curve.
The basic principles for formulating metal heating specifications are high quality, high efficiency, and low consumption. The aluminum billet is required to have no heating defects (cracks, overheating, overheating, gasification, and less decarburization), uniform temperature, short heating time, and high production efficiency during the heating process. High efficiency, fuel saving, etc.
