What is the difference between casting and forging?

There are many processes with similar names in industry, but there are great differences between them, such as casting and forging.

Introduction to casting and forging

Casting: molten liquid metal fills the mold cavity for cooling, and air holes easily occur in the middle of the parts; Heat and melt the metal and pour it into the sand mold or mold. After cooling, it will solidify into a utensil.
Forging: It is mainly formed by extrusion at high temperature, which can refine the grains in the parts. The metal material in the plastic state can be turned into a workpiece with a certain shape and size by hammering and other methods, and its physical properties can be changed.

The difference between casting and forging

1. Different manufacturing processes

Casting is a one-time forming. After the metal is melted into liquid, it is poured into the casting cavity corresponding to the shape of the part, and then it is cooled, solidified and cleaned, so as to obtain the processing method of parts or burrs. The casting specialty focuses on the metal melting process and the process control in the casting process.
Forging is slow forming. The forging machine is used to exert pressure on the metal scrap, squeeze, hammer and other methods to make the metal material in the plastic state become a processing method with a certain shape and size of workpiece. Forging is a plastic forming under solid state, which can be divided into hot processing and cold processing, such as extrusion drawing, pier roughening, punching, etc

2. Different uses

Forging is generally used for the processing of forgings with certain shape and size. Casting is a relatively economic method for forming rough defects, and is generally used for parts with complex shapes

3. Different advantages

Forging advantages:

Forging can eliminate defects such as as-cast porosity produced in the smelting process of metal, optimize the microstructure. At the same time, because the complete metal flow line is preserved, the mechanical properties of forgings are generally better than those of castings of the same material. For the important parts with high load and severe working conditions in relevant machinery, forgings are mostly used except for the plates, profiles or weldments with simple shapes that can be rolled.
Casting advantages:

1. It can produce parts with complex shapes, especially blanks with complex inner cavities.

2. Wide adaptability. Metal materials commonly used in industry can be cast, from a few grams to hundreds of tons.

3. Wide source of raw materials and low price, such as scrap steel, scrap parts, chips, etc.

4. The shape and size of the casting are very close to the parts, which reduces the cutting amount and belongs to non-cutting processing.

5. It is widely used. 40%~70% of agricultural machinery and 70%~80% of machine tools are castings.

4. Disadvantages are different

Forging defect: In forging production, it is easy to cause trauma accidents
Casting defects:

1. Mechanical properties are inferior to forgings, such as coarse structure and many defects.

2. In sand casting, single piece, small batch production and high labor intensity of workers.

3. The casting quality is unstable, there are many processes, the influencing factors are complex, and many defects are easy to occur.