APA has a steel melt with out as much at pH 8 = 5.01 secondary is pH 7 pH = 4.01, sections 5, 6 have similar values of approximately 2.0-2.1 the minimum pH of 4 is equal to 0.04.
PH content of the molten iron out most at pH 8 = 5.01 lower at pH 7 and pH = 4.01 5,6 have similar values about 2.0 to 2.1. PH 4 at least equal to 0.04.