Corrosion Failure Analysis of Pins of High Frequency Transformer

The reasons for corrosion failure of after-sale high frequency transformers were studied through energy spectrum analysis of corrosion products in field, 0.2% (mass fraction) H₂SO₄ acid spraying test and 5% (mass fraction) NaCl salt spraying test. The results show that there was obvious sulfur element in corroded pins of high frequency transformers, and the corrosion of pins was more serious in wet, acid and salt spray environments. The iron substrate of pins with damaged coating corroded seriously, and corrosion was induced easily on the border of enamelled wire and solder. Using phosphor bronze as pin material and coating exposed enamelled wires with varnish water as protection layer could improve the corrosion resistance of pins effectively.