تحسين خاصية الحماية من التآكل للصلب المنخفض الكروم في البيئات الرطبة

Abstract EN

Chromium steels are used in the construction of petroleum and petrochemical industries because of their ability to passivity and protect themselves against corrosion.

but with a low amount of chromium, higher corrosion rates of these steels in moist atmospheres have been reported.

P-5(5%Cr) and P-91 (9%Cr) steels were subjected to isothermal oxidation tests.

these steels were tested in 21%H2O + 79%N2 gas mixture at 500oC by using a thermal gravimetric analysis (TGA) technique.

from the analysis, it was found that P-91 steel retained better oxidation resistance than P-5 in N2 + H2O environment.

the addition of free oxygen resulted in a reduction in the corrosion rate of P-5 steel by about 42%.

the improvement in corrosion property of P-5 steel could be achieved by either increasing the chromium content from 5 to 9% or addition of free oxygen 4 times the amount of H2O present in the environment.