A car is composed of numerous components, each of which plays a different role and needs to be processed through different processing techniques before it can be installed on the car for use. What are the processes for processing automotive components?

1、 Forging and processing of automotive parts

In the automotive manufacturing process, forging is widely used as a processing method. The forging method is divided into free forging and model forging. Free forging is a processing method of forming metal blanks by placing them on an anvil to withstand impact or pressure (commonly known as "forging"). The rough parts of automotive gears and shafts are processed using the method of free forging.

2、 Casting and processing of automotive parts

Casting is the production method of obtaining products by pouring molten metal into the cavity of the mold, cooling and solidification. In the process of processing and manufacturing automotive parts, many parts are made of cast iron into blanks, accounting for about 10% of the total weight of the vehicle, such as the cylinder body, transmission case, steering case, rear axle case, brake drum, various brackets, etc.

Sand molds are usually used to manufacture cast iron parts. The raw material for sand molds is mainly sand, which is mixed with binders, water, etc. The sand mold material must have a certain adhesive strength in order to be molded into the desired shape and be able to resist the erosion of high-temperature molten iron without collapse. In order to create a cavity in the sand mold that matches the shape of the casting, it is necessary to first make a model out of wood, called a wooden mold. After the hot molten iron cools down, its volume will decrease. Therefore, the size of the wooden mold needs to be increased according to the shrinkage rate based on the original size of the casting, and the surface that needs to be machined should be correspondingly thickened.

3、 Welding and processing of automotive parts

Welding is a processing method of joining two pieces of metal together by local heating or simultaneous heating and pressure. We commonly see workers holding masks in one hand and welding tongs and electrodes connected to wires in the other hand. The welding method is called manual arc welding, which uses the high-temperature melting of welding rods and weldments generated by arc discharge to make them join.

Manual arc welding is not widely used in automotive manufacturing. Spot welding is widely used in automobile body manufacturing. Spot welding is suitable for welding thin steel plates. During operation, two electrodes apply pressure to the two steel plates to make them stick together, and at the same time, the bonding point (a circular shape with a diameter of 5-6 甽) is heated and melted by current to firmly bond. When welding two car body parts, their edges are welded at intervals of 50-100 °, forming a discontinuous multi-point connection between the two parts. Welding the entire car body usually requires thousands of welding points. The strength requirements of solder joints are very high, and each solder joint can withstand a tensile force of 5kN, even tearing the steel plate, but still cannot separate the solder joint parts.