Abstract:
The present invention has as its object to provide a laser welded joint excellent in joint strength preventing a bead from cracking and comprised of exactly the number of weld beads required for joint strength and a laser welding method for the same in overlay laser welding of steel sheets forming multiple ring-shaped weld beads. The present invention is a laser welded joint excellent in joint strength preventing a bead from cracking and comprised of exactly the number of weld beads required for joint strength in overlay laser welding of steel sheets forming multiple ring-shaped weld beads, produced by a step of overlaying a plurality of metal sheets and forming a first weld bead and a step of firing a laser beam to successively form a further two or more weld beads at the outside of the first weld bead by laser irradiation, the surface hardness of the weld bead increasing from the inside bead to the outside bead.
Abstract:
There is provided a high-strength electric resistance welded steel pipe having excellent bendability. The electric resistance welded steel pipe includes a composition containing, on a mass% basis, C: 0.04% to 0.15%, Si: 0.10% to 0.50%, Mn: 1.0% to 2.2%, P: 0.050% or less, S: 0.005% or less, Cr: 0.2% to 1.0%, Ti: 0.005% to 0.030%, and Al: 0.010% to 0.050%, the balance being Fe and unavoidable impurities, and a microstructure including polygonal ferrite with a volume fraction of 70% or more and retained austenite with a volume fraction of 3% to 20%, the balance being at least one selected from martensite, bainite, and pearlite, wherein the polygonal ferrite has an average grain size of 5 µm or more and an aspect ratio of 1.40 or less.
Abstract:
There are provided: (1) A welding material for Ni-based heat resistant alloy has a chemical composition of: C:0.08 to 0.12%; Si ‰¤ 0.10%; Mn ‰¤ 1.50%; P ‰¤ 0.008%; S ‰¤ 0.002%; Ni: more than 56.0% to 60.0%; Co: 8.0 to 12.0%; Cr: 18.0 to 22.0%; Mo: 6.0 to 10.0%; Ti: 0.01 to 0.50%; Al: 0.50 to 1.00%; N ‰¤ 0.010%; O ‰¤ 0.010%; Nb: 0 to 0.50%; B: 0 to 0.0050%; Ca: 0 to 0.050%; Mg: 0 to 0.050%; and REM: 0 to 0.20%, with the balance: Fe and impurities, wherein the thickness of an oxide layer formed on the surface of the welding material is 30 µm or less; (2) a weld metal formed using the above welding material for Ni-based heat resistant alloy; and (3) a welded joint formed of the above weld metal and a base metal of a Ni-based heat resistant alloy excellent in high temperature strength.
Abstract:
A control system (1) for controlling an exhauster (10; 12) for a cutting device operable to cut a sheet (20), said control system (1) comprising processing and control means (4, 6, 8) configured to adjust an exhausting power of said exhauster during cutting of the sheet (20) on the basis of at least one operating parameter among: type of material of said sheet, type of cutting device used, position of cutting on the sheet, percentage of the sheet already cut or of the sheet still to be cut.