94 85 93 na na 93 97 nainhibitor sup a 39 0 0 0 na na 4 34 55corrosionrating immersedportion ofcoupon 1 8 2 2 2 6 2 3 1 3 7vapor liquidline oncoupon 1 1 1 1 1 2 5 5 2 3 3__________________________________________________________________________ sup a detection limit for hydrazine in final solution is approximately 1 ppm b n sub 2 h sub 4 2hcl c n sub 2 h sub 4 h sub 2 o d n sub 2 h sub 4 h sub 2 so sub 4 na not analyzed in a similar manner mono and dialkyl hydrazines may be similarly useful corrosion inhibitors as hydrazine since the chemistry of hydrazine is not basically altered by substitution of one or two hydrogen atoms by alkyl groups in any event the data show that even at the relatively high chlorate concentrations encountered in the tests hydrazine is a surprisingly effective corrosion inhibitor in caustic alkali solutions at concentrations in the range between about 50 and 1000 ppm based on the weight of the solution expressed in terms of its proportion to the chlorate present in the solution hydrazine has been found in these laboratory tests to be an effective corrosion inhibitor when used in a proportion in excess of 5 of the stoichiometric amount of hydrazine required for complete destruction of chlorate e g about 10 to 50 or more based on stoichiometry and the weight of the chlorate it appeared to be insufficiently effective in these.