Defects and Prevention of Liquid-state Die Forging Parts
Liquid-state die forging is a forming method of deforming metal parts with a certain shape at high temperature and certain pressure. It also has high requirements for product quality, and often appears at specific locations of liquid-state die forging part defects. This paper will discuss the defects and prevention measures of liquid-state die forging parts.
The first common defect in liquid-state die forging parts is pore. The formation of pores is related to the conditions of forging process and material performance. Firstly, the pores are caused by the off-pressure holes that remain in the die forging blank. Secondly, due to the low temperature of the die forging blanks, the liquid-state forging parts can produce some shrinkage pores in the process of liquid-state forging. Thirdly, it is also caused by the too slow pouring speed and the poor performance of the die material itself. In order to prevent the pore defects, the liquid die forging process must be strictly implemented and the pouring speed should be appropriate.
The second type of common defect in liquid-state die forging parts is star crack. Star cracks appear mostly on the surface of the parts. The cause of star crack formation is usually related to the internal cracks or uneven distribution of material in the blanks, which affects the performance and forming of the parts. In the hot state of the die forging parts, the parts have strong plastic deformation, which will cause the internal cracks to produce star cracks. In order to avoid star crack defects, the blanks should be polished first and their heats should be coordinated.
The third most common defect in liquid-state die forging parts is scratch shape. Scratch shapes often occur on the surface of the parts. The cause of the scratching is that there are too many burrs on the head of the die forging parts, which affect the gloss of the original parts. In order to prevent the scratching of the parts, the surfaces of the die parts must be uniform and clean, and the impact of burrs must be avoided.
The fourth common defect of liquid-state die forging parts is oxide scaling. Oxide scaling is basically related to the molten state of the die forging parts. Due to the low temperature of the die forging parts, the liquid-state die forging parts are prone to produce oxide scaling, which affects the strength and performance of the parts. In order to prevent the defects of oxide scaling of liquid-state die forging parts, the temperature of the die must be uniform and the temperature of the die forging parts must be appropriate.
In summary, liquid-state die forging parts are prone to some common defects during the forming process, such as pores, star cracks, scratches and oxide scales. In order to avoid the defects of these parts, the process parameters of die forging must be strictly controlled, and the temperature and material distribution of the die forging process should be coordinated. With the correct measures, the surface quality and performance of forged parts can be effectively improved, and the products formed are of high quality and can meet the needs of industrial use.
