電解加工における各種加工液の加工特性について

Abstract

In this report the machining characteristics of some electrolytes for carbon steel (S 15 C) and austenitic stainless steel (SUS 27) were experimentally investigated. The electrolytes were sodium chloride solution including sodium sulfite, sodium chloride solution including sodium hexametaphosphite and calcium chloride, sodium nitrite solution, potassium bromide solution, and sodium chlorate solution, which are less corrosive for mild steel than sodium chloride solution. The main results are as follows.(1) In the case of sodium chlorate solution the two materials can not be machined by single-phase half-wave current, but by square wave current. The surface finishes by the latter are slightly worse than those in sodium chloride solution, but the machined forms are rather sharper. The surface roughness is not affected by the pH value of the solution in the range from 6 to 11.(2) In the case of other electrolytes better surface roughnesses are obtained by square wave current than by single-phase half-wave rectified current. The surface roughness of carbon steel is not affected by the kind of electrolyte, and the surface roughnesses are within a range from 4 to 6 μ Hmax. The surface roughnesses of austenitic stainless steel are within a range from 1 to 2 μ Hmax in other electrolytes besides potassium bromide solution.