Welding steel and manufacturing method thereof

The welding steel, [C] is 0.065% 0.010% inclusive, [Si] is 0.20% less than 0.05% or less, [Mn], 2 1.52% or more. 70% or less, [Ni] is 1.50% 0.10% inclusive, is [Ti], 0.015% 0.005% inclusive, [O] is 0.0010% or more 0.0045% hereinafter, [N] is 0.006% or 0.002% or more or less, the [Mg], 0.003% 0.0003% or more or less, [Ca] is 0.003% 0.0003% or more or less, contain elements, the balance includes iron and unavoidable