HOT ROLLED STEELS HAVING EXCELLENT CRUSHING RESISTANCE AND FOR USE IN OIL WELL TUBE AND METHOD FOR PRODUCING THE SAME AND STEEL PIPE PREPARED BY THE SAME

摘要

The present invention provides a steel pipe and a hot rolled steel sheet for an oil-well pipe having excellent crushing resistance without thermal treatment after manufacturing the pipe, excellent yield strength, and excellent tensile strength. The present invention comprises: 0.3-0.4 wt% of C; 0.05-0.5 wt% of Si; 1.0-2.5 wt% of Mn; 0.02 wt% or less of P; 0.01 wt% or less of S; 0.001-0.006 wt% of Ca; 0.01-0.06 wt% of Al; 0.008 wt% or less of N; 0.1-0.5 wt% of Cr; and the remainder consisting of Fe and unavoidable impurities.