METHOD FOR PRODUCING A NICKEL-IRON-CHROMIUM-ALUMINIUM WROUGHT ALLOY WITH INCREASED ELONGATION IN THE TENSILE TEST

摘要

Method for producing a nickel-iron-chromium-aluminium alloy comprising (in % by weight) 12 to 40% chromium, 0 to 4.0% aluminium, 0.01 to 75.0% iron, 0.001 to 3.0% silicon, 0.001 to 4.0% manganese, 0.0 to 1.0% titanium, 0.0001 to 0.05% magnesium and/or calcium, 0.005 to 0.25% carbon, 0.0005 to 0.050% nitrogen, max. 0.020% oxygen, max. 0.030% phosphorus, max. 0.010% sulphur, optionally 0 to 4% niobium, optionally 0 to 30% molybdenum, optionally 0 to 30% tungsten, optionally between 0.0 and 15.0% cobalt, optionally between 0 and 0.008% boron, the remainder nickel and the usual process-related impurities, a) by means of melting in an induction or arc furnace followed by treatment in a VOD or VLF installation or by means of melting in a vacuum induction furnace (VIM), b) followed by cleaning by means of electroslag remelting (ESR), optionally also additionally cleaning with VAR, wherein the electroslag remelting, optionally also VAR, achieves increased elongation in tensile testing in the temperature range from 500 to 900°C, which leads to a reduction in the sensitivity to stress relaxation cracks (SRC) in this temperature range.