Forging is a combination of forging and stamping, is the use of forging machinery hammer, anvil block, punch or through the die to exert pressure on the blank, so as to produce plastic deformation, so as to obtain the required shape and size of the workpiece forming processing method. Yamanishi Yongxin believes that forgings are metal formed by forging after solid state heating. It requires the metal to have good thermoplasticity (also known as forging), the general forgings are steel parts, its high strength, good plasticity, suitable for the manufacture of large forces, high requirements of important parts. Such as bolts, shafts, gears, etc.
Casting metal is formed by pouring liquid into the mold. It requires liquid metal to have good fluidity and filling (also known as casting), steel castings are divided into cast steel and cast iron two, cast iron higher carbon content than steel, its strength is lower than steel, plasticity is poor, generally suitable for the production of bearing capacity is not too large parts, such as machine tool body, low pressure valve seat; Steel castings have high strength and are used to make parts with complex shapes, such as chain rails and high pressure valve seats.
Counting and cutting is one of the important links to improve the utilization rate of materials and realize the finish of blank. Too much material not only causes waste, but also aggravates mold wear and energy consumption. If the material is not left a little margin, it will increase the difficulty of process adjustment and increase the scrap rate. In addition, the quality of the blanking end face also has an impact on the quality of the process and forging.
The purpose of heating is to reduce the forging deformation force and improve the metal plasticity. But heating also brings a series of problems, such as oxidation, decarbonization, overheating and overburning. Accurate control of initial and final forging temperature has great influence on product structure and properties.
Flame furnace heating has the advantages of low cost and strong applicability, but the heating time is long, it is easy to produce oxidation and decarbonization, and the working conditions need to be constantly improved. Electric induction heating has the advantages of rapid heating and less oxidation, but it has poor adaptability to changes in product shape, size and material.
Forging forming is produced under the action of external forces, therefore, the correct calculation of deformation force is the basis for selecting equipment and mold verification. The stress and strain analysis of the inside of the deformed form is also indispensable to optimize the process and control the microstructure properties of the forging.
The work of forging quality analysis can be divided into the field investigation stage, the test research and analysis stage, and the solution and prevention measures. Before the implementation of these stages of work, it is best to develop an implementation plan, including the work to be carried out in these three stages, work procedures, and completion time. The implementation plan may be appropriately supplemented and modified during the implementation process. Making the implementation plan is an important link to analyze the quality problems of large complex forgings and use parts.
In the field investigation stage, it is mainly to investigate the material grade, chemical composition, material specifications, test results on the material guarantee sheet of the raw materials used in the forging, the results of various physical and chemical tests and process performance tests in the factory, and even to identify the smelting and processing technology of the raw materials.
At the same time, the forging process should also be investigated, including the swing material, specifications, blanking process, the initial forging and final forging temperature of forging heating, the forging equipment used, the heating equipment, the heating process, the forging operation, the cooling method after forging, the process of preparing heat treatment, etc.
If necessary, the operator's condition and environmental conditions and the original records of the execution process are also investigated. For forging quality problems that occur in subsequent processes and use, the process of subsequent processes should also be investigated.
Through the above detailed examination of the forging process, we can see that every link is crucial from the selection of raw materials to the final forming of the forging. The precise control of the forging process not only ensures the high quality of the forgings, but also reflects the relentless pursuit of the fine process in the manufacturing industry. With the continuous progress and innovation of technology, the future forging process will be more efficient and intelligent, and continue to provide a solid material foundation and technical support for the industrial field.
