Choice of die materials for auto parts forging
Apr 30, 2023| 1. Overview of auto forging parts
Auto parts refer to the parts and accessories used to replace, repair or upgrade the original parts in the manufacturing, assembly and maintenance of automobiles. Forging is an important class of auto parts. Forged parts are metal parts that are typically treated with special heat and pressure to plastic deform at high temperatures to form shapes. Auto forging parts mainly include engine parts, chassis parts, steering parts, transmission parts, etc.
Auto forging parts usually need to withstand important loads under complex working conditions such as high temperature, high pressure and high speed. The manufacturing requirements for forging parts are very strict, not only need to meet the functional performance requirements, but also consider the cost of forging, precision and manufacturing cycle and other factors. In the process of forging parts manufacturing, die is one of the most critical components, is to determine the accuracy of forging parts, strength, life and a series of important factors.
Therefore, many factors must be considered when choosing the die material of forging parts, such as the performance of forging materials, forging process and product requirements. In this paper, we will describe in detail how to select suitable die materials to manufacture auto forging parts.
2. Classification of mold materials
Die is an important equipment used to manufacture forging parts. In die manufacturing, the choice of its material has a great influence on the quality of the product. The selection of mold materials usually needs to consider the following factors:
2.1 Plate material
Plate material refers to the materials used to manufacture templates, including low alloy steel, medium carbon alloy steel, high speed steel, etc. Plate materials usually have high hardness, high strength, high wear resistance, good thermal stability and fatigue resistance, suitable for manufacturing large, complex and high precision pressure tools and complex shape cutting tools.
2.2 Tool Steel
Tool steel refers to steels of high strength, high wear resistance and high thermal stability used in the manufacture of dies for stamping, extrusion and casting. Tool steel is characterized by high hardness, high strength, good wear resistance, good toughness, not easy to deformation and good fatigue resistance, which is suitable for manufacturing large and medium-sized molds.
2.3 Special steel materials
Special steel materials refer to materials used in the manufacture of special molds, such as stainless steel, corrosion resistant steel, superalloy, heat resistant steel, wear resistant corrosion resistant steel and nickel base alloy. These steels have the characteristics of high temperature, high strength and high corrosion resistance. They can withstand high temperature, high pressure and high speed operating environment. They are suitable for manufacturing high precision and high demand molds, such as high pressure casting molds, injection molds, extrusion molds, etc.
3. Selection of mold materials
In the manufacture of auto forging parts, die is a very important component, especially for large and high precision forging parts. When choosing the die material of forging parts, the forging process and the performance of forging materials should be taken into account first. In the establishment of forging process, it is necessary to clearly define the mechanical properties, physical properties, chemical properties, high temperature properties and other important parameters of forging materials, so as to select the appropriate die materials.
3.1 Properties of forging materials
The forging materials have high temperature and stress, and need to have good high temperature strength and thermal stability, and can withstand large extrusion pressure and effusive pressure, in order to meet the quality and size requirements of the forging parts. If the mechanical properties and thermal stability of forging materials are poor, it will lead to cracks, defects and deformation of forging parts.
In general, the high temperature strength, toughness, corrosion resistance and thermal stability of forging materials are the key factors in the selection of die materials. For example, when making engines or steering parts, it is necessary to choose die materials with high temperature strength and good heat resistance.
3.2 Forging process
Forging process is another important factor in choosing the die material for forging parts. The forging process is usually divided into cold forging and hot forging.
Cold forging refers to metal working performed at room temperature. Cold forging usually requires the use of materials with high hardness, strength and wear resistance. Commonly used materials are high carbon alloy steel, high speed steel, molybdenum steel and so on. Cold forging has the advantage of being able to achieve high accuracy and smooth surfaces, but is generally less productive than hot forging.
Hot forging refers to metal working at high temperatures. In the process of hot forging, the metal is deformed under high temperature and high pressure, so it is necessary to use materials with high thermal stability, good wear resistance, high strength, high hardness and high toughness, such as tool steel and superalloy. The advantage of hot forging is that a large number of high quality forgings can be produced quickly, but the requirements for materials and molds are also high.
3.3 Product Requirements
Product requirements are another important consideration in choosing die materials. In determining the mold material, it is necessary to understand the size, shape, material, quantity, product precision requirements and other factors of forging parts, so as to choose the appropriate mold material.
For example, when manufacturing large forgings, it is usually necessary to choose materials with high strength, high hardness and good wear resistance, and cooperate with the use of high-efficiency lubricants with long life to improve production efficiency and reduce production costs. In the manufacture of high precision forgings, it is necessary to choose materials with high fatigue resistance, high thermal stability and high toughness.
4. Application of mold materials
4.1 Mild Steel
Low carbon steel refers to the carbon content of the steel is not more than 0.25%, its carbon content is low, wear resistance and strength are relatively low, but has good plasticity and toughness. Low carbon steel is one of the most common die materials, suitable for the manufacture of hot renewal auto forging parts.