Bearing processing knowledge: Stainless steel grinding
1) Wheel easy-adhesion blocked; 2) the processing surface is easy to burn;
3) hardening phenomenon is serious; 4) of the workpiece deformation.
Not difficult to see, select the grinding wheel and grinding fluids directly affect grinding efficiency and machining accuracy. This article blockage affecting the adhesion and surface roughness factors experiment.
2 Experimental conditions and methods
Specimen material selection 1Gr18Ni9Ti, its mechanical properties: σb = 530MPa, σ = 40%, hardness HB = 187 specimen size diameter φ50mm, length 300mm, φ50 cylindrical surface finishing, both ends of the playing surface the center hole. Experiments on MGB1420 cylindrical grinder, grinding wheel of P400 × 40 × 203, cylindrical grinding grinding way, to improve the reliability of test results, repeat the test, observe the average effect, eliminate the influence of random factors, at the same time Try to keep grinding conditions remain basically unchanged, by changing the wheel size, hardness, abrasive, grinding fluid replacement, grinding parameters to examine the impact on the grinding effect.
3 experimental results
3.1 Effect of wheel size on the adhesion rate of
Selection of corundum, hardness K, respectively, four wheel size 36,46,60,80 number of specimens cylindrical grinding, grinding length of 600mm, detection adhesion rate, the finer the grinding wheel, stick attached more serious, this is due to the presence of voids between the grains, grinding chips can be stored in the cavity; and while finer grinding wheel, voids smaller wheel quickly lose the chip space, causing blockage.
3.2 Wheel hardness affect adhesion rate
Selection abrasive is corundum, size 46, hardness was H, J, K, L grade wheel of specimen grinding, grinding stroke 600mm, detecting adhesion rate. The higher the hardness of the wheel, the more severe adhesion. This is due to the low hardness of the grinding wheel, abrasive in grinding force, is easily accessible from the wheel off the surface, forming a new chip space, easy to plug.
3.3 abrasive adhesion rate
Commonly used abrasive wheel has corundum and silicon carbide green two kinds of experiments show that the impact of the two abrasive adhesion rate, the difference is not big, green silicon carbide may slightly reduce the sticking, because the brittle and sharp.
3.4 Effect of grinding fluid on the surface roughness
Three were using liquid emulsion, mineral oil-based grinding fluid and grinding fluid, adding sulfur, chlorine and other extreme pressure additives, observe machined workpiece surface roughness, grinding fluid flow is 20L / min, grinding stroke of 600mm, the experimental results as shown in Table 3.
As it can be seen from Table 3, the surface tension and containing extreme pressure additives, surface quality obtained by grinding. Rational use of grinding fluid, can improve the thermal conditions of grinding and grinding fluid can wash away debris and grit off, while the metal surface to form a film, a lubricant, reducing the surface roughness.
3.5 grinding parameters affect the adhesion rate
Workpiece speed, feed rate and grinding depth has little effect on the process, can be seen from Table 2, changing the depth of grinding, it has little effect on the adhesion rate.
