Abrasion-resistant steel
Provided is an abrasion-resistant steel including a predetermined chemical composition, in which content (mass %) of Mo and B satisfy Mo×B>0.0010, a mass fraction of Mo 2 FeB 2 is from 0.0010 to 0.10%, an area ratio of martensite in a central portion in a thickness direction is 70% or more, Ceq obtained by the following (Formula 1) is 0.80% or less, and a plate thickness exceeds 50 mm; Ceq =C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5 (Formula 1) wherein, in (Formula 1), C, Mn, Cu, Ni, Cr, Mo, and V are contents (mass %) of each element.
1. An abrasion-resistant steel, comprising, by mass %:
C: 0.10 to 0.40%,
Si: 0.05 to 0.50%,
Mn: 0.50 to 1.50%,
B: 0.0015 to 0.0050%,
Mo: 0.60 to 2.50%,
Al: 0 to 0.300%,
S: 0.010% or less,
P: 0.015% or less,
N: 0.0080% or less,
Ti: 0 to 0.100%,
Nb: 0 to 0.100%,
Cu: 0 to 1.50%,
Ni: 0 to 2.00%,
Cr: 0 to 2.00%,
V: 0 to 0.20%,
Ca: 0 to 0.0100%,
REM: 0 to 0.0100%,
Mg: 0 to 0.0100%,
W: 0 to 2.00%, and
a balance: Fe and impurities, wherein:
contents (mass %) of Mo and B satisfy Mo×B>0.0010,
a mass fraction of Mo 2 FeB 2 is from 0.0010 to 0.1000%,
an area ratio of martensite in a central portion in a thickness direction is 70% or more,
Ceq obtained by the following (Formula 1) is 0.80% or less, and
a plate thickness exceeds 50 mm;
Ceq =C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5 (Formula 1),
wherein, in (Formula 1), C, Mn, Cu, Ni, Cr, Mo, and V are contents (mass %) of each element.
2. The abrasion-resistant steel according to claim 1 , wherein a mass fraction of Fe 23 (C, B) 6 is 0.0020% or less.
3. The abrasion-resistant steel according to claim 1 or 2 , wherein the contents (mass %) of Mo and B satisfy Mo×B≥0.0015.
4. The abrasion-resistant steel according to claim 1 or 2 , wherein the contents (mass %) of Mo and B satisfy Mo×B≥0.0020.
5. The abrasion-resistant steel according to claim 1 or 2 , wherein a content (mass %) of Mo satisfies from 0.70 to 2.50%.