Martensitic

Martensitic stainless steels for seamless steel pipe

by crusher0806 on Mar 18, 2011

This invention relates to martensitic stainless steels used in seamless steel pipe
such as oil-well pipe and pipeline tubing. Martensitic stainless steels, two representative grades of which are SUS 410 and SUS 420 (Japan Industrial Standard ?JIS! designations), have excellent corrosion resistance in highly corrosive environments containing CO2. These materials are thus regarded as excellent candidates for use in oil-well pipe, geothermal well pipe, and pipeline tubing.

The strength of oil-well pipe is normally required to be least equivalent to that of American Petroleum Institute (API) standard L80 grade steel (yield strength≥80 ksi). Pipeline tubing should Generally have a strenoth at least equal to that of API standard X60 grade steel (yield strength≥60 ksi).

Compositions in which the austenite phase (which becomes martensite at room temperature) exists in combination with a ferrite phase comprising 20-30% of the composition have the worst...Read More >>