Wear-resistant steel balls wear failure related factors

Wear - due to mechanical action caused by the gradual loss of surface material. Wear failure - due to material wear and tear caused by mechanical products lose their function. The abrasive grinding steel balls wear loss throughout the proportion exceeds 50%. The so-called abrasive wear: by entering an external hard particles or the friction surface between the projections on the surface of softer material plow dig a lot of grooves, resulting in the migration of materials caused by a kind of wear and tear. Analysis of the wear mechanism wear ball shall be considered from mechanical wear and tear of the external environmental conditions and grinding steel balls intrinsic properties of two ways.

Mechanical wear and tear of the external environmental conditions: There are several aspects hardness, strength, speed, angle, temperature, humidity, size and so on.

1, the hardness of the abrasive: wear many features, the most important impact of material hardness.

2, intensity; especially where the pressure on the abrasive material. As the pressure increased wear, the wear amount increases, because as the pressure is increased to increase the penetration depth of abrasive wear of the balls, the cutting material surface deformation energy increases.

3, the speed of the mill: for different types of wear, and wear rate is different. Sliding wear down, affecting the speed is not obvious. Erosion has a major impact on the wear rate, when the impact speed is high to a certain extent, had not caused at low speed sliding wear or worn materials at this time also can cause wear and tear.

4, angle: Influence of erosion wear on impact angle is very large. Different effects and impact angle of brittle materials ductile materials. For brittle materials such as ceramics, wear amount increases with the increase of the angle, at approximately 90 ° angle in a vertical impact conditions, the maximum amount of wear, which indicates that the brittle material is unsuitable for use in high angle erosion conditions; for ductile materials , the angle of impact with the first amount of wear increases, reaches a maximum at a certain angle, with the subsequent increase of the amount of wear of the impact angle of fall. This indicates that the material toughness at low angles work conditions prone to wear and tear, but in a high angle can give full play to its wear resistance. This is because the toughness of the material is low hardness, low angle of the cutting surface of the abrasive erosion most advantageous amount of wear that is rising, while the brittle material impact in the vertical surface of the material most easily broken flake, so the maximum amount of wear.

5, temperature: as the temperature increases with the increase of wear.

6, Humidity: practical engineering, in the case of metal friction, wear liquid access to the interface, it can wear greatly reduced; but in the case of abrasive wear, abrasive moisture to enter, but the wear becomes serious.

7, size: abrasive grain size: the initial impact on the wear as the particle size increases the wear increases linearly, when reaches a certain critical value of the so-called particle size, abrasion growth becomes slow, or there growth is no longer the case.

More significantly, the relative hardness of the abrasive material, or the hardness ratio. From the large number of tests on the abrasive wear found that a relationship between the ratio in Figure 2 and the amount of wear material hardness and abrasive hardness. Figure 2 H1 and H2, respectively M1 and M2 material hardness. Two different materials with hardness abrasive wear volume change and hardness change during wear volume variation ratio of both materials, and in Figure 2, for a relatively soft material M1, when less than the hardness of the abrasive material hardness H1 when, with the increase in the hardness of the abrasive wear rises slowly, and when the hardness of the abrasive material hardness increased to about wear and tear on the most sensitive abrasive hardness, when abrasive hardness exceeds the hardness of the material, to continue to improve the hardness of the abrasive wear no effect on . For hard materials M2 also the same variation, the wear can be summed up into three zones: Ⅰ low wear area, Hs (1.25 ~ 1.13), where Hm is the hardness of the material, the hardness Hs of the abrasive, excessive wear Ⅱ 0.8Hs; ⅲ high wear area, Hm <1.25Hs. Low wear zone Ⅰ: in region Ⅰ wear is not serious, far higher than the hardness of the workpiece material, the wear and tear caused by the workpiece effective component material is not processed, but where a small amount of impurities, high hardness, these account for only a few percent impurities control the wear process. Wear transition zone Ⅱ: Most wear often occurs in Ⅱ area, then the hardness of minerals and close to the workpiece, increasing the hardness of the workpiece can significantly improve the wear resistance of the workpiece, in this case for failure analysis and selection of wear-resistant materials instructive.

When further increased abrasive hardness, high wear Ⅲ enters the area, this time not with the abrasive grinding steel balls hardness increases or increases too slowly in this area blindly increase the hardness of the material, help to improve the wear, and increased costs.