EXPANDABLE OIL WELL PIPE TO BE EXPANDED IN WELL AND PROCESS FOR PRODUCTION OF THE PIPE

摘要

The invention relates to an oil well pipe for pipe expansion which is to be expanded in a well. The oil well pipe has both a chemical composition which contains by mass C: 0.05 to 0.08%, Si: 0.50% or below, Mn: 0.80 to 1.30%, P: 0.030% or below, S: 0.020% or below, Cr: 0.08 to 0.50%, N: 0.01% or below, Al: 0.005 to 0.06%, Ti: 0.05% or below, Cu: 0.50% or below, and Ni: 0.50% or below with the balance being Fe and impurities and a structure having a ferrite content of 80% or above. Further, the oil well pipe exhibits a yield strength of 276 to 379MPa and a uniform elongation of 16% or above, thus being excellent in pipe expandability.