Sheng Lin mold experts describe the difference between casting molds and forging molds, can you tell the difference?

2019-11-20 16:47:00

In mold manufacturing, we usually hear casting and forging. What is the difference between these two manufacturing processes? Now, there are some experts from Shenglin Mould Machinery Factory to give us an analysis.

I. casting

Casting is the process of smelting metal into a liquid that meets certain requirements and pouring it into a mold. After cooling and solidifying and finishing, a casting (part or blank) with a predetermined shape, size and performance is obtained. It is a modern machinery manufacturing Basic industrial processes.

The cost of the blank produced by casting is low, and it can show its economy more for the parts with complex shapes, especially with complicated inner cavity. At the same time, it has a wide adaptability and good comprehensive mechanical properties. However, the materials required for casting production (such as metal, wood, fuel, modeling materials, etc.) and equipment (such as metallurgical furnaces, sand mixers, molding machines, core making machines, sand dropping machines, shot blasting machines, cast iron plates, etc.) It will cause dust, harmful gas and noise to pollute the environment.

1. There are many types of casting, which are customarily divided into:

①Ordinary sand mold casting, including wet sand mold, dry sand mold and chemical hardened sand mold.

② Special casting, according to the molding materials, can be divided into special castings with natural mineral sand and gravel as the main molding materials (such as investment casting, mud casting, shell casting in foundry, negative pressure casting, solid casting, ceramic casting) Etc.) and special castings (such as metal casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.) with metal as the main mold material.

2. The casting process usually includes:

① Preparation of casting molds (containers for making liquid metal into solid castings). Casting molds can be divided into sand, metal, ceramic, clay, and graphite according to the materials used; they can be divided into disposable and semi-permanent according to the number of uses. And permanent. The quality of the mold preparation is the main factor affecting the quality of the casting;

② Melting and pouring of cast metals. Cast metals (cast alloys) are mainly cast iron, cast steel and non-ferrous alloys;

③ Casting processing and inspection. Casting processing includes removing foreign matter from the core and the casting surface, cutting out the riser, shovel and burr, and other protrusions, as well as heat treatment, shaping, rust prevention and rough processing.

2. Forging

Forging is a processing method that uses a forging machine to apply pressure to a metal blank to plastically deform it to obtain a forged piece with certain mechanical properties, a certain shape and size. It is one of the two major components of forging.

Through forging, the as-cast looseness and welding holes of the metal can be eliminated, and the mechanical properties of the forging are generally better than those of the same material. For the important parts with high load and severe working conditions in the machinery, in addition to the simpler shapes that can be rolled plates, profiles or welded parts, forgings are mostly used.

1. Forging is divided by forming method

① Open forging (free forging)

The impact force or pressure is used to deform the metal between the upper and lower stern irons (anvils) to obtain the required forgings. There are mainly manual forging and mechanical forging.

② Closed mode forging

Metal blanks are deformed by compression in a forging die cavity with a certain shape to obtain forgings, which can be divided into die forging, cold heading, rotary forging, and extrusion.

2. According to the deformation temperature

Forging can be divided into hot forging (the processing temperature is higher than the recrystallization temperature of the billet metal), warm forging (below the recrystallization temperature), and cold forging (normal temperature).

Forging materials are mainly carbon steel and alloy steel with various components, followed by aluminum, magnesium, titanium, copper, and their alloys. The original state of the material is bar, ingot, metal powder and liquid metal. The ratio of the cross-sectional area of the metal before deformation to the die area after deformation is called the forging ratio. The correct choice of forging ratio has a lot to do with improving product quality and reducing costs.