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Hydraulic Valve Casting Has A Particularly Important Role

Yutung Industrial Limited | Updated: May 15, 2017

Hydraulic Valve Casting and forging are two different processing techniques. Hydraulic Valve Casting is the shape of the molten metal into a solid shape. Hydraulic Valve Casting valve is cast into the valve, the general Hydraulic Valve Casting of the valve pressure levels are relatively low (such as PN16, PN25, PN40, but also high pressure, can go to 1500Lb, 2500Lb), caliber most of the DN50 or more.

The forging is mainly in the high temperature with the extrusion method of forming. You can refine the grain in the workpiece. Forging the valve is forged out, are generally used in the high level of the pipeline, the caliber is relatively small, generally below DN50. Today, Xiao Bian for everyone finishing in the valve forging some of the basic knowledge, we learn and reference.

One, the type of forging

(A) according to the deformation temperature classification

When the temperature exceeds 300-400 ℃ (steel blue brittle zone), to 700-800 ℃, the deformation resistance will be drastically reduced, deformation energy has also been greatly improved. According to the different temperature areas forging, forging quality and forging process requirements can be divided into cold forging, warm forging, hot forging three molding temperature area. The recrystallization temperature of the steel is about 727 ° C, but generally 800 ° C is used as the dividing line, hot forging higher than 800 ° C; between 300 and 800 ° C is called warm forging or semi-hot forging. Do not heat at room temperature forging called cold forging.

At low temperature forging, the size of the forging varies little. In 700 ℃ below forging, the formation of less oxide, and the surface without decarburization phenomenon. Therefore, as long as the deformation can be in the range of forming energy, cold forging easy to get a good dimensional accuracy and surface finish. As long as the control of good temperature and lubrication cooling, 700 ℃ below the warm forging can also get very good accuracy. Hot forging, due to deformation and deformation resistance are very small, you can forge the shape of the complex large forgings. To obtain high-precision forgings, can be 900-1000 ℃ temperature field with hot forging processing. In addition, pay attention to improve the hot forging work environment. Forging die life (hot forging 2-5 thousand, warm forging 1-2 million, cold forging 2-5 million) compared with other temperature field forging is shorter, but its degree of freedom, low cost The

The blanks are deformed and hardened during cold forging, allowing the forging to withstand high loads. Therefore, high-strength forging and high-strength hardening film treatment methods are used. In addition, in order to prevent billet cracks, if necessary, the middle annealing to ensure the required deformation capacity. In order to maintain a good lubrication state, the blank can be phosphating treatment. In the continuous processing with the bar and wire rod, the current section can not be used for lubrication treatment, is studying the possibility of using phosphating lubrication method.

(B) according to the movement of the blank classification

According to the movement of the blank, forging can be divided into free forging, upsetting, extrusion, die forging, closed forging, closed upsetting.

1, free forging

Definition: the use of impact or pressure to make the metal in the upper and lower anvil between the direction of free deformation, without any restrictions on the required shape and size and certain mechanical properties of a forging a processing method, referred to as free forging.

Features: free forging tools and equipment used is simple, versatile and low cost. Compared with the Hydraulic Valve Casting rough, free forging in addition to shrinkage, shrinkage, pores and other defects, so that the blank has a higher mechanical properties. Forging shape is simple, flexible operation. Therefore, it is in the heavy machinery and the manufacture of important parts of a particularly important significance.

Category: There are two kinds of manual forging and mechanical forging. Manual free forging production efficiency is low, labor intensity, only for repair or simple, small, Hydraulic Valve Casting small batch forging production.

Hydraulic Valve Casting In modern industrial production, machine free forging has become the main method of forging production, in heavy machinery manufacturing, it has a particularly important role. The resulting shape and size of the forging is mainly determined by the technical level of the operator.

Hydraulic Valve Casting Major equipment: free forging equipment is divided into forging hammer and hydraulic press two categories. Production for the use of forging hammer with air hammer and steam - air hammer, and some plants also use the structure is simple, less investment spring hammer, plywood hammer, lever hammer and wire hammer and so on. Hydraulic press is the liquid produced by the static pressure of the blank deformation, is the only way to produce large forgings.