RESEARCH ON PREVENTION METHOD OF INTERCRYSTALLINE CORROSION FOR 1Cr18Ni9Ti SEAMLESS STEEL PIPE

The intercrystalline corrosion is one of the most dangerous destruction forms for austenite stainless steel pipe. Through the reason analysis of the intercrystalline corrosion,many factors are induced which have affected the 1Cr18Ni9Ti seamless steel pipe intercrystalline corrosion. And the effective methods are proposed to prevent the intercrystalline corrosion. There are many effective methods as follows: decreasing the carbon,the phosphorus and harmful impurity element content;Increases the few stable elements titanium,suitably increases the chromium content,reducing the nickel content;In 1 050~1 100℃ carring on the solid solution treatment,the quick speed cools,suppresses separates out the carbide in the crystal boundary;In 850~880℃ under carries on the stable processing for 2~4 h,then slow cooling;In needs to carry on the cold finishing and in under the suitable sensitization temperature processing situation,follows first the cold finishing,after but carries on the heat treatment the principle;Through processing and heat treatment crystal grain size control in 6~8 levels.