Laws of formation of surface roughness when abraded, and the conditions for its reduction

New analytical relationships of defining cutting temperatures at multipass surfacing with regard to the heat getting into the part being machined and the chips have been got in this work from cutting temperature calculation at grinding by simplified method. It has been shown in this paper that the main part of the heat at multipass grinding gets into the part being machined while just little heat gets into the chips.That is why calculation of the heat getting into the part being machined brings theory of grinding in compliance with the practice. It has been stated in theory that density change type of the heat flow into the surface layer of the part being machined does not influence considerably either on the absolute value or cutting temperature at grinding change type or on the heat penetration depth into the surface layer of the part being machined. It is in good compliance with the experimental research results of the heat penetration depth into the surface layer of the part being machined which сorroborates the theory and its practical use possibility for determination of optimum conditions of cuttimg at multipass grinding from temperature. It has been shown that conventional cutting stress decrease influencing greatly on the cutting temperature is the main condition of cutting temperature decrease. It has been stated in theory that cutting temperature at grinding can be decreased, specific efficiency given, by grinding depth decrease, that is by multipass grinding. It has also been stated as opposed to the known solutions of heat conduction classic equation at grinding when heat penetration depth into the surface layer is infinite and thus the true value of the distorted layer (the layer is imperfect as regards the thermal effect) the heat penetration depth into the surface layer in this solution is finite