Standard Practice for Macroetch Testing of Tool Steel Bars

Abstract

This practice covers macroetch testing used for evaluating the quality of tool steel bars. This test shall be used as a quality control and inspection test to reveal by deep acid etching, the macrostructure in specimens cut from bars and to show the presence, absence, and severity of the following internal, surface, or subsurface conditions: pipe, bursts, carbide or alloy segregation, nonmetallic inclusion concentrations, porosity, cracks or thermal flakes, seams, laps, ingot corner segregation, pinholes, foreign material, and ingot pattern. Macroetching may be performed in a vessel of borosilicate glass, porcelain, corrosion-resistant metals, or some other acid resisting material. The etching reagent, specimen sampling, specimen preparation, and testing procedure including etching temperature, etching time, and macroetching technique are detailed.