Mamoru Nakayama

Experimental study of grinding fluids for abrasive-belt grinding of stainless steel

Abstract A number of ferritic stainless steels with high corrosion resistance have recently been developed, but these steels are known to be difficult to grind in coated abrasive-belt grinding operations. In order to formulate or select an optimum oil-based grinding fluid with which such stainless steels can be successfully ground, an optimum base oil was first experimentally selected, and then additives were evaluated for their effect in improving abrasive-belt grinding performance. A paraffinic mineral oil having a certain viscosity was found to be suitable for the base oil. Chemical grinding oil additives were found markedly effective in improving the abrasive-belt grinding performance for both 19Cr-2Mo ferritic stainless steel and SUS 304 austenitic steel, with those containing sulphur or chlorine being superior to those containing phosphorus, fatty acid or alcohol. Among all the additives tested, chemically active oils, such as sulphurized mineral oil, exhibited the best performance. Effects of chlorinated paraffins on the grinding performance could be perceived but were not so great as those of sulphur-series additives. The addition of TCP (tricresyl phosphate) to the grinding oil containing sulphur reduced metal removal in the case of 18Cr-2Mo ferritic stainless steel (SUS 444). In the case of SUS 430 ferritic stainless steel, however, TCP increased metal removal for a comparatively low sulphur concentration, but, above an optimum concentration of 0.4 wt% S, metal removal was reduced by TCP addition. A comparison of sulphur-series additives added to a sulphurized paraffinic mineral oil showed that nonyl polysulphide was superior to any other additives for improving the grinding performance in 19Cr-2Mo steel (SUS 444) and SUS 430. Excess addition of sulphurized fatty oil to a grinding fluid lowered the cutting ability of abrasive grains.

Effect of nonylpolysulphide in different base oils on abrasive belt grinding of stainless steel

Abstract Nonylpolysulphide was added to a single paraffinic base oil, P60, and a blended paraffinic base oil, BP60, and its effect was examined experimetally. Adding nonylpolysulphide to a base oil had a greater effect with the single base oil, P60, than with the blended base oil, BP60, if the grinding condition could be correlated to the sulphur concentration. With the blended base oil, nonylpolysulphide was found to improve the grinding performance in a comparatively wide range of sulphur concentrations.

Effect of blended paraffinic base oils on abrasive belt grinding of stainless steel

Abstract The effect on grinding performance of blended paraffinic base oils of about the same viscosity was examined experimentally with a newly improved apparatus, in which a pressurized air cylinder is installed as the work infeed system. Stock removal was not affected by the kinds of blended base oil, however, abrasive belt wear decreased with the blended base oil as compared with the single base oil.

Effect of EP-additives in grinding oil upon grinding performances - Cylindrical plunge grinding of stainless steels.:Cylindrical Plunge Grinding of Stainless Steels

以上の結果をまとたると,次のようになる.(1)研削比の向上には極圧添加剤の効果は大きい。すなわち,研削比はSの場合が最も大きく,そしてP,C1の順である.(2)SUS304の場合,研削条件が過酷になると凝着を起こし,本実験の場合いかなる添加剤でもそれを防げなかった.しかし,それを軽減する効果はSが最も大きかった.(3)仕上面粗さの向上には,いずれの被削材に対してもPの効果が大きい.(4)研削抵抗はSUS304,SUS440Cのいずれに対しても,P,C1,Sの順に小さくなる傾向があり,特に法線研削抵抗にその傾向が顕著に現れる.(5)本実験条件の範囲内では,SUS440CはSUS304ほど難削材ではない.