Analysis of the Causes of Cracking on the Tensile Surface of Wear-resistant Steel NM400

Wear-resistant steel NM400 plays an important role in modern engineering and is widely used in various fields, such as mining industry, construction machinery, and so on. However, some cracking problems have been found on the tensile surface of wear-resistant steel NM400. Cracking may cause failure of the parts or components, and thus, it is necessary to investigate the causes of the problem in order to solve it.
    
1. Stress Concentration:
One of the possible causes of cracking on the tensile surface of wear-resistant steel NM400 is stress concentration. Many external loads and internal forces acting on the wear-resistant steel can easily lead to the stress concentration on the surface. The concentration of stress on the surface will exceed the strength of the material, resulting in cracking. In order to prevent this problem, designers should use suitable ways to evenly distribute the stress.
    
2. Thermal Stress:
The cracking of wear-resistant steel NM400 may also be caused by thermal stress. The rapid cooling of the hot material will cause the thermal stress on the surface of wear-resistant steel NM400, which will result in cracking. Therefore, the design of the cooling system or the choice of materials must be taken into consideration to reduce or avoid the thermal stress.
    
3. Metallurgy Defects:
The metallurgical defects of wear-resistant steel NM400 may also be the cause of cracking on the tensile surface. Poor quality of smelting or mixing may cause defects such as pores or uneven structure, which can lead to fatigue cracking. Therefore, it is necessary to check the quality of the smelting and mixing of the material before using it.
    
4. Poor Workmanship:
The poor workmanship may also be the reason for cracking. For example, improper machining, such as too large cutting depth, too large RPM of cutting, or too large cutting speed, will lead to the surface roughness, which eventually cause surface cracking. Therefore, the machining process must be strictly controlled to ensure the quality.
    
In conclusion, cracking on the tensile surface of wear-resistant steel NM400 may be caused by stress concentration, thermal stress, metallurgy defects and poor workmanship. In order to solve these problems, designers should use suitable ways to reduce stress concentration, take care of the thermal stress and metallurgical defects, and strictly control the machining process. With proper control, the cracking problem on the tensile surface of wear-resistant steel NM400 can be effectively solved.

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