Questions of Metal Fabrication

Metal fabrication is common in today’s manufacturing, during this process, we may find there are so many questions that we have not noticed before. Today, this short essay will talk about the questions you may meet in metal fabrication.

List: 

1. Kinds of Questions of Metal Fabrication

2. Solutions of Questions of Metal Fabrication

Kinds of Questions of Metal Fabrication

• Burrs in Metal Fabrication

• Corrosion in Metal Fabrication

• Oil Mist in Metal Fabrication

Solutions of Questions of Metal Fabrication

• Burrs in Metal Fabrication

Steel is the most common type of metal, with low price and high strength. The disadvantage is that it is easy to corrode and rust. The rust resistance of rust inhibitors commonly used in metalworking oils during processing is critical. In the process of workpiece storage, the factors affecting steel rust are high content of metal processing oil bacterial derivatives, high humidity, and high acid value in the air. The solution to the problem of steel rust is to use oily cutting oil to prevent steel rust from occurring under the premise of ensuring processing quality.

Titanium is the metal with the highest strength-to-weight ratio and good corrosion resistance at room temperature, but poor thermal conductivity. Due to poor thermal conductivity, heat is easily concentrated on the contact surface of the cutting surface during processing, and stress corrosion cracking easily occurs under high temperature conditions of titanium metal. The method for solving the corrosion problem of titanium metal is to use precision cutting oil for processing titanium alloy. The special cutting oil for titanium alloy not only has excellent cooling performance, but also provides excellent extreme pressure anti-wear performance and effectively protects cutting tools.

The advantage of aluminum is its low density and its low corrosion resistance, but in some cases aluminum can also cause corrosion problems. For example, exposure to certain metal salts (such as chloride), the pH is too high, and contact with other metals to form galvanic corrosion. The solution to the problem of aluminum corrosion is to use vulcanized lard as the main extreme pressure additive to reduce the proportion of chlorinated paraffin, which can effectively prevent the occurrence of aluminum corrosion problems.

Magnesium metal has a small density but high strength but is chemically active, and reacts with water to form hydrogen which is flammable and explosive. This problem is particularly noticeable when using water-based processing fluids. Solving the corrosion method in magnesium processing is to use pure oily cutting oil instead of water-based cutting fluid, and conduct corrosion test on metal processing oil and magnesium sheet before processing to judge the strength of reaction between metal processing oil and magnesium. Pay attention to the degree of corrosion of the magnesium sheet.

• Corrosion in Metal Fabrication

Burr refers to the irregular metal parts, such as sharp corners and rough edges, which are produced by grain shear slippage and plastic deformation during metal cutting (including hot and cold processing) under the action of cutting force, resulting in material extrusion and tearing, resulting in the transition of workpiece surface. We can reduce the surface roughness of the tool rake face; increase the tool rake angle; reduce the cutting thickness; properly heat treatment of the workpiece to reduce plastic deformation; establish an ultra-stable processing environment and other methods to avoid the occurrence of burrs. However, the burrs on the workpiece always appear more or less. At this time, we need to pay attention to effectively remove the burrs before the heat treatment of the workpiece, so as to avoid the burrs are not easily removed after the heat treatment.

• Oil Mist in Metal Fabrication

In order to protect valuable tools during metal cutting, improve the surface precision of the metal, prevent the occurrence of "knife knobs", etc., often use a large amount of lubricant to cool the lubricated workpiece and the cutting edge. These oils produce a large amount of oil mist when they are pumped, sprayed, and subjected to intense impacts and high temperature objects. Because these oil mists contain various additives, salts, aliphatic amines, oxides, heavy metals and other substances, together with these oil mist particles are too small, some less than PM2.5 will directly enter the human respiratory tract leading to asthma, skin diseases, paronychia and other occupational diseases. In order to solve this question, we can use low oil mist cutting oil; that is, the oil of the cutting oil blended with the base oil with higher refining depth and higher viscosity will be less extinguished. Another method is to use a cutting oil containing a high-scoring polymer oil mist inhibitor e. Also, it is the most thorough and ideal measure to improve the ventilation of the plant or to add a strong exhaust fan.

From all the information we give above, we believe that you have already known the questions you will meet during metal fabrication and you also have known the solutions to solve them or ease them.