| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-rolled high-strength thin steel sheet which is superior in stamped-hole expandability and has small variations thereof, as a steel sheet for automobiles. SOLUTION: The high-strength thin steel sheet superior in stamped-hole expandability includes, by mass%, 0.01 to 0.1% of C, 0.01 to 2% of Si, 0.05 to 3% of Mn, 0.1% or less of P, 0.03% or less of S, 0.005 to 2.0% of Al, 0.01% or less of N, 0.0005 to 0.0030 of B, further Ti in a range that satisfies the expression of Ti-(48/12)C-(48/14)N-(48/32)S≥-0.03%, and the balance Fe with unavoidable impurities. A value of variations of the hardness of the steel sheet divided by the average value thereof is 0.2 or less, and the face intensity of a face ä110} in a rolling direction of the steel sheet is 1.7 or less. COPYRIGHT: (C)2009,JPO&INPIT
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