What are the process requirements for machine tool castings?

Machine castings mainly include large machine castings, lost foam machine castings, resin sand machine castings, and machine bed castings. Bed casting products, as large castings, must be heat treated to improve their own performance and improve the intrinsic quality of cast iron plates. Metal heat treatment is one of the important processes in mechanical manufacturing. Heat treatment usually changes the internal microstructure of the workpiece or changes the chemical composition of the workpiece surface without changing the shape and overall chemical composition of the workpiece, thereby improving or improving the performance of the workpiece. Its characteristic is to improve the internal quality of the workpiece.

1. Machine tool castings

The production of machine bed castings adopts a complete resin sand production line, and all resin sand castings are used. The material of the machine casting is high-quality high-strength cast iron HT250-300, which has strong resistance, high dimensional accuracy, uniformity, no buckles, and no flash or burrs on the castings. The surface is smooth and close to precision casting, and the internal structure is stable. The entire production process of the machine tool bed is pollution-free, and the three-level environmental protection can eliminate or reduce casting defects such as sand holes and pores.

2. Main uses of machine tool castings

Machine castings have the advantages of high dimensional accuracy, good rigidity, small machining allowance, excellent surface quality, etc. They are easy to operate, shorten production cycle, and improve production efficiency. They are widely used in instrumentation, standard parts, bearing industry, electronics, light industry, auto parts industry and other parts processing, especially suitable for non-ferrous metals. Machine castings have good wear resistance and consumability. Low melting point, good fluidity, and small shrinkage. Mechanical bed standard mechanical casting standard GB9439-88 bed casting features: good wear resistance and consumability. Cast iron graphite is conducive to lubrication and oil storage, so it has good wear resistance. Similarly, due to the presence of graphite, its consumability is better than steel. Good process performance

3. Advantages of machine tool casting materials

The resin sand mold has good rigidity, and conditionally utilizes the graphitization expansion during the solidification process of cast iron to effectively eliminate shrinkage holes and shrinkage defects, and realize small risers and murad bottom casting of gray cast iron and ductile iron.

Heat treatment process As a large casting, bed casting products must be heat treated to improve their performance and improve the intrinsic quality of cast iron castings. Metal heat treatment is one of the important processes in mechanical manufacturing. Heat treatment usually changes the internal microstructure of the workpiece or changes the chemical composition of the workpiece surface without changing the shape and overall chemical composition of the workpiece, thereby improving or improving the performance of the workpiece. Its characteristic is to improve the internal quality of the workpiece.

4. Casting method of machine tool castings

Sand casting is preferred for machine tool castings, because sand casting is lower in cost than other casting methods, the production process is less mechanized, and the production cycle is not long, so the quality can also be guaranteed. If wet punishment does not meet the requirements, you can consider using plasticine Shaxi dry death penalty, dry death penalty or other death penalty. The weight of clay wet sand castings can reach several kilograms to tens of kilograms, and castings weighing tens of tons are mostly produced by clay dry molds.

5. Overall heat treatment

Overall heat treatment is a metal heat treatment process that heats the workpiece as a whole and then cools it at an appropriate rate to change the overall mechanical properties. Generally speaking, there are four basic processes for the overall heat treatment of steel, namely annealing, purification, tempering, and tempering. Annealing methods The general annealing processes of heat treatment annealing types include recrystallization annealing, stress relief annealing, spherical annealing, and complete annealing.