Laboratory tests have been made, on SUS 27 stainless steel, to study the corrosive effect, at temperaturs of 550∼700°C, of oil ash deposits in 4 oil fired boilers.The chemical constituents and the meltingpoints of the deposits had been also determined.
Conclusions after testing were as follows:
(a) The deposits having higher V205/Na20 ratio were more corrosive.
(b) In many cases deposits contained a component melting at about 570°C.M
(c) All of the deposits were less corrosive at bellow 570°C.
(d) The corrosive effect of the deposits on superheaters, whose steam temperaturs were 540°C and 570°C, was lowest.
(e) The wastage of SUS 27 stainless steel in one year by air oxidation in the deposits. on the secondary superheaters, at 600°C, was estimated at below 0.2 mm.
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