Prediction of microgeometry in pendulous grinding of plane parts made of steel 13Х15Н4АМ3 by high porous wheels

The grinding process is used at the final stage of manufacture of responsible parts. The quality criterion in this case is surfaced roughness that determining machine durability. Abrasive wheels are the weakest link in process technology system, which cutting abilities can’;t be expressed as a deterministic quantity. In this connection the assessment of cutting properties of abrasive wheels is conducted with attraction of parametric and nonparametric statistical methods that allow to find not only expected measure of position (mean, median), but also a measure of scattering, estimated by deviations standards, swings and interquartile widths. The measures of scattering are seldom considered in estimating of cutting ability of abrasive wheel, although they only allow to characterize the stability of the process. This is especially important in processing of large operating batches of parts on customized machines. The research is conducted with high porous wheels (VPK) of new generation, which porosity was increased to (10-12)th structure and high-strength grains of cubic boron nitride (CBN50 100/80 СТ1 10К27 100-КФ40) and microscopical corundum (5SG 46I 12 VXP) are used. It is revealed that the difference between expected means and medians is in the limit of categorical variables (CV), and the most accurate estimates of process stability are obtained with deviations of standard. Grinding of flat parts made of steel 13Х15Н4АМ3 should be occurred with wheels made of synthetic corundum 5SG that allows to decrease the high parameters of roughness - 1,12-1,16 times higher (that means one CV) and increase the process stability in 1,04-1,06 times.

grinding, high roughness parameters, statistics, mean, median, deviation of standard