In the working process of wear-resistant plate parts, media and materials often have a variety of effects on the workpiece. The main failure modes are as follows:
(1) Wear failure
The main failure mode of wear-resistant plate is wear failure. Wear failure is a process of material loss or deformation on the contact surface of two objects when relative motion occurs. Many factors in the wear condition will have a great impact on the wear resistance of the material, such as the liquid concentration and acid-base property in the wet condition, the particle size and hardness of the abrasive, the load borne by the parts and so on.
In some cases, when the abrasives contact with the workpiece, they often rub the workpiece repeatedly, resulting in abrasive wear. At the same time, they are often accompanied by impact and rolling action, resulting in plastic deformation of the workpiece. To a certain extent, the surface of the wear-resistant plate will produce grooves or even fall off. For example, the side guide plate of the hot rolling coiler is used to align the strip steel with the rolling center line and send it to the pinch roll, and the guide plate holds the strip steel when entering the pinch roll to reduce the tower shape of the coil. The guide plate at the front end will be scratched and impacted by the sharp angle of the strip steel during the initial guide, and then when the clamped strip steel enters the pinch roll, the surface of the side guide plate will rub with the strip steel to produce a groove. In the working condition, there will be chemical and electrochemical reactions at the same time, resulting in corrosion and wear. For example, for the lining plate of ball mill, the material will not only fall or drop in the barrel of ball mill, impact the lining plate in the foot area, but also produce micro cutting effect on the lining plate due to sliding or rolling on the surface of the lining plate. Under the wet grinding condition, the slurry will also corrode the lining plate and accelerate the loss of lining plate material. The main corrosion forms of lining plate are strain differential cell corrosion, crevice corrosion and pinhole corrosion.
In addition to the above, fatigue wear may occur due to the falling off of the wear-resistant plate due to cyclic alternating stress, or adhesive wear of the same material may occur in high temperature environment. In the production practice, several kinds of wear often exist at the same time and influence each other, which is the joint action of many kinds of wear mechanisms, but at the same time, there is always a kind of wear mechanism that plays a leading role. Therefore, when analyzing the wear of wear-resistant plate, it is necessary to find out the specific working condition, the type of wear and the wear mechanism.
(2) Fracture failure
Fracture failure refers to the process of fracture and loss of service performance of parts. It is the most important and dangerous failure of mechanical products. Its classification is relatively complex, mainly including primary fracture, brittle fracture, fatigue fracture, intergranular fracture, creep fracture, etc. When the impact force of the medium and material on the wear-resistant plate is very large, if the toughness of the workpiece is poor, the repeated impact will often lead to its fatigue fracture. Fracture failure usually occurs in an instant, resulting in immeasurable loss.
(3) Bulge deformation
During the installation of wear-resistant plate parts, certain assembly requirements must be met. During the working process, the medium and material will impact and rub the surface of the workpiece, or when the material itself is in a certain high temperature state, it will generate or conduct certain heat on its surface. In some cases, due to the contact between the material and the workpiece, the temperature difference between the internal and external surfaces will lead to the surface stress of the plate, while when the yield strength of the workpiece can not meet its stress demand, the workpiece will be convex deformation, affecting the use.