All forgings production, 60 to 70% of the forgings is sand production, and about 70% of the production of clay sand. The main reason is sand forging low cost compared with other forging methods, the production process is simple, short production cycle. Like a car engine cylinder block, cylinder head, crankshaft, forged with the production of green sand process. Forging when wet type can not meet the requirements to consider the use of clay sand dry sand, dry sand or sand. Forging the forging weight of green sand from a few kilograms up to tens of kilograms, while the clay dry production of forgings weighing dozens of tons.
In general, for the medium and large forgings, forging the resin self-hardening sand, forged steel water glass sand production, you can get the accurate size and smooth surface of the casting, but the cost is higher. Of course, the sand stainless forging precision, surface finish, material density and microstructure, mechanical properties are often poor, and other forging methods should be used when these performance requirements of the forging higher, such as investment casting (lost December) forging, press forging, low pressure forging and so on.
The forging method and production quantities to adapt. Such as sand forged, mass-produced factory should create the conditions for using advanced technology and styling, making the core method. Forging old-fashioned shock or shock-compression molding machine production line productivity is not high enough, the workers' labor intensity, noise and does not meet the requirements of mass production should gradually be modified. Horizontal or vertical box-free high-pressure molding machine production line can be used for small forgings, Real styling and high production efficiency, the area is also less; can be used for the pieces of the high-pressure molding machine production line of various boxes, gas impact molding line to adapt to the fast, high-precision molding production line requirements, core making methods can be selected: the cold-box, hot-box, shell core, and efficient system of core methods.
Moderate quantities of large forging can be considered the application of resin self-hardening sand molding and core making. Single small-batch production of heavy forgings, hand-shape is still important, and hand molding to adapt to a variety of complex requirements more flexible, and does not require a lot of technology and equipment. Can the application of sodium silicate sand, water glass sand of the VRH law, organic ester water glass from the hard sand, clay, dry, resin from the hard sand and cement sand, etc.; pit molding method for the single production of heavy forgings, low cost, and put into operation fast. Mass or long-term production of styling products with multi-box modeling, split box modeling method is more appropriate, although the mold, sand box, started to invest in, but can be compensated from the shape of saving man-hours, improve product quality.
|
