Valves are used in chemical system air separation equipment, and most of the sealing surfaces are made of stainless steel. In the grinding process, due to improper selection of grinding materials, grinding method is not correct, not only reduces the valve production efficiency, but also a considerable impact on product quality. According to the characteristics of stainless steel materials, we have chosen to have a strong labor intensity and wear resistance, but also in the processing of abrasive grain still affect the product quality. In recent years, our formula for grinding materials can maintain the cutting edge of the abrasive materials, such as white corundum and chromium oxide and grinding tools and grinding methods such as the use of research, the size of the main selection w40, w14, w7 and W5, etc. Four is appropriate Through the test, and in the actual production has been promoted and applied, both to improve the quality of the sealing surface, but also improve the production efficiency, get very good results.
Valve grinding of the workpiece is the first grinding tool sand, and then by means of abrasive and grinding fluid mixture composed of grinding agent to achieve the purpose of grinding. The abrasive force refers to the force acting on the unit surface area, which is applied to the tool and acts on the surface to be machined by the abrasive grains. If the pressure is too small, the grinding effect is small and the pressure increases, The grinding effect is enhanced and the grinding efficiency is improved. However, when the pressure increases to a certain value, that is, saturation phenomenon, the grinding efficiency of the general situation to reach the maximum, then continue to increase the pressure per unit area, the efficiency but decreased.
This is because the valve abrasive has a certain pressure limit, when more than this limit will be crushed, so that abrasive grain thinner, grinding self-reduced. Therefore, in the choice of unit pressure should be based on the abrasive strength and crushing characteristics of the decision after the test, the general should use the following parameters: ① in the rough research, the white corundum abrasive, select 0.2 ~ 0.5MPa. ③ in the lapping, the white cut jade abrasive, select 0.03 ~ 0.12MPa.
Grinding speed refers to the speed of the relative movement of the tool surface. The grinding speed is an important process parameter for controlling the amount of removal, removal rate and processing surface quality.Figure 2 is the typical relationship between the workpiece size removal, the surface roughness and the grinding speed.
The role of the research tool and its material research is to make the grinding agent for temporary fixation and get a certain grinding movement, and its own geometry in a certain way to pass to the workpiece. Therefore, the material of the manufacturing tool should have the proper embedding property and the accuracy of the geometry of the abrasive grains for long-term retention. Gray cast iron HT200 is the ideal material for the production of research tools, the organization of both hard wear-resistant cementite, but also tough plastic good ferrite, but also contains graphite components, played a lubricating effect, and easy to shape and processing The
The grinding time required to obtain the required surface quality is greater than the time required to remove the margin, and the grinding speed should be appropriately reduced. After the test, the following speed value is appropriate: ① in the rough research, the grinding tool or grinding the workpiece to the speed of 20 ~ 50m / min. ② three fine valve in the fine grinding, the grinding tool or grinding the workpiece speed of 6 ~ 12m / min. 6. Selection of surface roughness value Surface roughness is one of the main indicators of surface quality. On the surface function has a great impact on the surface wear, contact stiffness and sealing performance have a direct effect, while affecting the use of product performance and life. With different grinding methods and particle size, the surface roughness achieved is also different.