Hot-rolled steel sheet for gas nitrocarburizing and manufacturing method thereof

A hot-rolled steel sheet for gas nitrocarburizing comprising, by mass %,

• C content [C]:
• C of more than 0.07% and equal to or less than 0.2%,
• Si content [Si]:
• Si of 0.001% or more and 2.5% or less,
• Mn content [Mn]:
• Mn of 0.01% or more and 4% or less, and
• Al content [Al]:
• Al of 0.001% or more and 2% or less,
• P content [P] limited to 0.15% or less,
• S content [S] limited to 0.03% or less, and
• N content [N] limited to 0.01% or less,
• Ti content [Ti] which satisfies the following Equation 1, and
• the balance consisting of Fe and unavoidable impurities,
• wherein an average pole density of an orientation group of {100}<011> to {223}<110>, which is represented by an arithmetic average of a pole density of each orientation of {100}<011>, {116}<110>, {114}<110>, {112}<110>, and {223}<110> is 1.0 or more and 4.0 or less, and a pole density of a crystal orientation of {332}<113> is 1.0 or more and 4.8 or less, in a center portion of a sheet thickness which is a range of the sheet thickness of ⅝ to ⅜ from a surface of the steel sheet,
• wherein an average grain size in a center in the sheet thickness is 10 μm or less, and
• wherein a microstructure includes, by a structural fraction, pearlite of more than 6% and ferrite in the balance,
• 0.005+[N]×48/14+[S]×48/32≦Ti≦0.015+[N]×48/14+[S]×48/32 (1).