A method of manufacturing the electron beam welded joints for steel plate and electron beam welded joints

摘要

The composition of the steel, in mass%, this electron beam welded joint, C: 0.02% ~0.1%, Si: 0.03% ~0.30%, Mn: 1.5% ~2.5 %, Ti: 0.005~0.015%, N: 0.0020~0.0060%, Al: 0.05% or less than 0.004%, Nb: 0% ~0.020%, V: 0 % ~0.030%, Cr: 0% ~0.50%, Mo: 0% ~0.50%, Cu: 0% ~0.25%, Ni: 0% ~0.50%, B: 0 % ~0.0030%, Ca: 0% ~0.0050%, P: 0.015% or less, S: 0.010% or less, O: A content of 0.0035% or less inevitable balance iron and It consists of impurities, electron beam welding hardenability index value CeEB is a 0.60% 0.49%, in the center of plate thickness, 20 is the number of inclusion particles of 1.0μm or more circle equivalent diameter / mm ² or less, equivalent circle diameter containing more than 10% Ti is 10 ³ / mm ² or more and 1 × number of particles of less than 0.5μm 0.05μm or more.