PRODUCTION METHOD FOR HOT ROLLED STEEL SHEET WITH BEAUTIFUL APPEARANCE

摘要

PROBLEM TO BE SOLVED: To provide a production method for a hot rolled steel sheet with beautiful appearance which is high P steel containing P at high concentration of 0.02 mass% or more and nonetheless is free from the occurrence of swelling or peeling of scales formed on a surface.SOLUTION: The production method for a hot rolled steel sheet containing P of 0.02 to 0.5% is provided in which a relationship between the content of P in the hot rolled steel sheet A (mass%) and a finish rolling start temperature T(°C) satisfies a relationship of T≤-33.35ln(A)+947.62 and coiling temperature after completion of finish rolling is 400 to 650°C and an average cooling rate from start of finish rolling to coiling is 20°C/sec or less.SELECTED DRAWING: None