The Effects of the Pickling Process on the Amount of Hydrogen Occluded in Steel Plate for Porcelain Enamel

Abstract

By direct estimation of the hydrogen content in the enameling steel of the composition C : 0.06, Si : 0.05, Mn: 0.44, P : 0.04, Cu : 0.32% by vacuum heating procedure the authors have confirmed the following facts. (1) The hydrogen absorbed in steel plate of 0.56 mm thick during the pickling with 10% sulphuric acid solution will be removed almost completely if the aftertreatment will be carried out according to the normal schedule. However, with the plate of 6 mm thick a part of hydrogen will remain obstinately even if the after treatments are strictly obeyed to the normal schedule. (2) If the schedule of after. treatment will be changed arbitrary or be simplified then a part of absorbed hydrogen may remain in steel plate so thin as 0.56 mm. (3) A large quantity of hydrogen will remain in steel plate especially when the latter has cavitie3, and a part of hydrogen accumlated in holes can not be removed by the prolonged heating at 70°C.