as sulfites and hydroxylamines 2 organic compounds such as quinoline toluidine and nitro phenols and 3 heavy metals such as copper nickel and chromium only the oxidizing agents have achieved major industrial importance as accelerators as is known in the art other additives may be included in the phosphating solution such as ph adjustors levelers and the like a preferred additive in accordance with the invention is a cyclic trimeta phosphate as disclosed in the above cited u s pat no 4 168 983 the concentration of the trimeta phosphate is preferably maintained low 0 001 moles per liter providing some benefit and increasing amounts providing increased benefits up to a maximum of about 0 15 moles per liter a preferred range varies between 0 01 and 0 1 moles per liter as the concentration increases above 0 15 moles per liter corrosion resistance drops off but then increases as the concentration reaches about 0 25 moles per liter consequently higher concentrations may be used but are less preferred because of cost and further at the higher concentration results are not easily reproducible and the good results are obtainable only with relatively fresh solutions any iron or steel part to which a phosphating coating has been applied in the prior art may be treated in accordance with the invention the part is prepared in accordance with prior art procedures and then immersed in a phosphating composition as described above typically at a temperature varying between about 150 u00b0.