Influence of Forging on Metal Structure and Properties and Forging Defects

Effects of Forging on Metallurgical Structure and Properties and Defects of Forgings

The comprehensive effects of forging process on metallurgical structure and properties involve several aspects, such as crystal structure, grain size, phase change and mechanical properties of the forged material. These effects are mainly due to thermal, plastic and mechanical processes in forging.

The most important aspect of the thermal process is the partial recrystallization, which effectively eliminates and refines the weak spots in ingot metallurgy structure and improves the metallographic and mechanical properties of the forging. Due to the intense thermal processing in the forging process, the mechanical process is mainly the refining of the recrystallization grains, the redistribution of the weak spots in the forging and then the tempering effect due to the rapid cooling of the forging.

The plastic process includes a variety of physical and chemical processes, such as a strain, pressure, indentation, diffusion and diffusion control. The most important aspect of the plastic process is the strain, which causes changes in the microstructure and type, such as deformation and grain refinement, as well as improved macroscopic mechanical properties. The pressure process causes the material to obtain a denser structure and improved mechanical property, while the indentation process causes a high strain rate and change in fatigue strength. Diffusion and diffusion control processes allow the element to enter and leave the structure of the material, which can improve the microstructure and mechanical properties of the forged material.

In conclusion, the forging process can effectively improve the microstructure and mechanical properties of the forged material, but can also lead to the occurrence of defects such as cracks and misalloyed sections. The most commonly occurring forging defects are surface defects, planar and volumetric defects, such as cracks, cold shuts, sink marks, non-uniform thickness, ingot shrinkage cavities, cavities, misalloyed sections, and so on. These defects are mostly caused by the improper selection of forging parameters, inadequate forging process control, incomplete or incorrect heat treatment, and incorrect processing or repair. Therefore, in order to improve the metallurgical structure and properties and reduce the defects of forgings, in addition to controlling the heat treatment properly, it is also necessary to properly select the raw materials, technological parameters and process parameters in the forging process, and to ensure the uniformity of the forging process control. Only in this way can the forgings meet the desired structure and properties, and reduce the occurrence of forging defects.

It is clear that forging has a significant influence on the metallurgical structure and properties of the forged material, and has a certain impact on the quality of the forgings. Therefore, it is of great significance to understand the effects of forging process on metallurgical structure and properties and the corresponding forging defects, so as to improve the forging process and forging quality, and improve the quality of forging products.

The Effects of Forging on Metal Structure and Performance and Forge Defects

Forging is a metalworking process that uses large amounts of pressure, heat, or a combination of both to deform metal into a desired shape. It is commonly used to form complex shapes and parts from a variety of metals, including aluminum and steel. The process of forging can have an effect on the structure, performance, and appearance of the metal depending on the type of forging used.

Cold forging is a process used to shape metal at room temperature. This type of shaping gives the metal a stronger, harder surface, as well as improved tolerance and ductility compared to working with hot metal. Although cold forging can be used to form some complex parts it is often best suited to simple shapes like bolts and screws.

Hot forging is the process of deforming metal under elevated temperatures. This allows the metal to become easier to work with, as the elevated temperatures make it more malleable. Additionally, hot forging can produce a much finer finishing to the part or object being formed. Hot forging can be used to make complex shapes and parts that couldn’t be produced with cold forging methods.

Drop forging is a very intensive process used to produce sturdy, intricate parts from a variety of metals. In this process, the metal is positioned between a die and anvil and struck with a hammer until it takes the shape of the desired form. This process can create intricate parts with enhanced strength, and can be used on a variety of metals including aluminum, stainless steel, and titanium.

Finally, roll forging is a process used to produce long, thin, and uniform cross sections of metal. This process involves placing the metal between two pairs of rolls which rotate in opposite directions and gradually flatten the metal as they pass over it. This type of forging is best suited to making long, thin parts such as nails and rods, as it is much faster than cutting the pieces by hand.

Forging can have an effect on the strength and durability of the metal depending on the process used. Although the various forging processes can produce parts of superior strength, they also can lead to defects such as cracking, warping, and distortion that can affect the overall performance of the part. Additionally, forging can add porosity to some metals which can alter the metals’ ability to conduct heat or electricity and thus reduce its performance.