| 摘要 |
<p>A steel material for electron-beam welding, said steel material containing, by mass, at least the following: 0.02-0.10% carbon, 0.03-0.30% silicon, 1.5-2.5% manganese, 0.005-0.015% titanium, 0.0020-0.0060% nitrogen, and 0.0010-0.0035% oxygen. The amounts of sulfur, phosphorus, and aluminum in said steel material are limited to at most 0.010%, at most 0.015%, and at most 0.004% by mass, respectively, with the remainder of said steel material comprising iron and unavoidable impurities. Said steel material has an index (CeEBB) of 0.42% to 0.65%, and in the thicknesswise middle of a cross-section of said steel material parallel to the thickness direction of the steel material, the number of oxides having equivalent circular diameters of at least 1.0 µm is at most 20 per square millimeter and the number of oxides that contain at least 10% titanium and have equivalent circular diameters of at least 0.05 µm and less than 0.5 µm is 103 to 105 per square millimeter.</p> |
