Hot rolled steel sheet
Provided is a hot rolled steel sheet having a predetermined chemical composition and a microstructure comprising, by area ratio, pearlite: 90 to 100% and pro-eutectoid ferrite: 0 to 10%, wherein the pearlite has an average lamellar spacing of 0.08 to 0.30 μm, and the percentage of cementite in the pearlite having a major axis length of more than 0.3 μm and an aspect ratio of less than 3.0 is less than 15%.
1 . A hot rolled steel sheet comprising a chemical composition comprising, by mass %,
C: 0.30 to 0.80%,
Si: 0.01 to 0.50%,
Mn: 0.50 to 2.00%,
P: 0.100% or less,
S: 0.0100% or less,
Al: 0.100% or less,
N: 0.0100% or less,
Cr: 0.30 to 1.00%,
Ti: 0 to 1.00%,
Nb: 0 to 0.10%,
V: 0 to 1.00%,
Cu: 0 to 1.00%,
Ni: 0 to 2.00%,
Mo: 0 to 0.40%,
B: 0 to 0.0100%,
Ca: 0 to 0.0050%,
REM: 0 to 0.005%, and
balance: Fe and impurities, and
a microstructure comprising, by area ratio,
pearlite: 90 to 100% and
pro-eutectoid ferrite: 0 to 10%, wherein
the pearlite has an average lamellar spacing of 0.08 to 0.30 μm,
the percentage of cementite in the pearlite having a major axis length of more than 0.3 μm and an aspect ratio of less than 3.0 is less than 15%,
the hot rolled steel sheet is not subjected to cold rolling, and
the tensile strength is 780 MPa or more and 1400 MPa or less.
2 . The hot rolled steel sheet according to claim 1 , wherein the chemical composition comprises, by mass %, one or more selected from the group of
Ti: 0.01 to 1.00%,
Nb: 0.01 to 0.10%,
V:0.01 to 1.00%,
Cu: 0.01 to 1.00%,
Ni: 0.10 to 2.00%,
Mo: 0.01 to 0.40%,
B: 0.0005 to 0.0100%,
Ca: 0.0005 to 0.0050%, and
REM: 0.0005 to 0.005%.
3 . The hot rolled steel sheet according to claim 1 , wherein the total elongation is 15% or more.
4 . The hot rolled steel sheet according to claim 2 , wherein the total elongation is 15% or more.
5 . The hot rolled steel sheet according to claim 1 , wherein the content of C is 0.30 to 0.65%.
6 . The hot rolled steel sheet according to claim 2 , wherein the content of C is 0.30 to 0.65%.
7 . The hot rolled steel sheet according to claim 3 , wherein the content of C is 0.30 to 0.65%.
8 . The hot rolled steel sheet according to claim 4 , wherein the content of C is 0.30 to 0.65%.
9 . The hot rolled steel sheet according to claim 1 , wherein the thickness is 1.0 to 6.0 mm.
10 . The hot rolled steel sheet according to claim 2 , wherein the thickness is 1.0 to 6.0 mm.
11 . The hot rolled steel sheet according to claim 3 , wherein the thickness is 1.0 to 6.0 mm.
12 . The hot rolled steel sheet according to claim 4 , wherein the thickness is 1.0 to 6.0 mm.
13 . The hot rolled steel sheet according to claim 5 , wherein the thickness is 1.0 to 6.0 mm.
14 . The hot rolled steel sheet according to claim 6 , wherein the thickness is 1.0 to 6.0 mm.
15 . The hot rolled steel sheet according to claim 7 , wherein the thickness is 1.0 to 6.0 mm.
16 . The hot rolled steel sheet according to claim 8 , wherein the thickness is 1.0 to 6.0 mm.