Abstract: A method for producing a welded rotor of a low-pressure steam turbine, the method including providing a first forging including a steel with a minimum yield strength of approximately 700 Mpa. A second forging is provided including a heat-treated 3.5 NiCrMoV stel having an average chemical composition of 3.5% of Ni, 1.5% of Cr, 0.35% of Mo, 0.10% of V, 0.25% of C, remainder Fe. A build-up layer of welding deposit is applied to a connection surface of the second forging using build-up welding. A first local post-weld stress-relief annealing is performed so as to soften the build-up layer and a corresponding heat-affected zone. The first and second forgings are joined together so as to provide a welding location. The welding location is filled using a welding deposit so as to provided a welded join. The welded join is subjected to a second post-weld stress-relief anneal.

Abstract: In a method for welding together two parts (12, 13), especially of a turbomachine, which are exposed to different temperatures, of which the first part (12) consists of a steel and the second part (13) consists of a nickel-base alloy which contains elements which are unfavorable for welding to steel, such as for example Nb, a crack-free welded joint is achieved by the fact that first of all an intermediate layer (18), in which the amount of unfavorable elements is progressively reduced from the inside outward, is applied to the joining surface (17) which is provided for the welding, and that then the second part (13), which has been provided with the intermediate layer (18), is welded to the first part (12).

Abstract: A method of forming a rotor comprises the step of welding a rotor element. The weld metal comprises: from 0.04 to 0.1% carbon, from 0 to 0.5% silicon, from 0.1 to 0.6% manganese, from 0 to 0.01% sulphur, from 0 to 0.03% phosphorous, from 1.9 to 2.6% chromium, from 0.05 to 0.3% molybdenum, from 0.2 to 0.3% vanadium, from 0.02 to 0.08% niobium, from 1.45 to 2.1% tungsten, from 0 to 0.03% nitrogen, from 0.0005 to 0.006% boron and from 0 to 0.03% aluminium. The rotor element may be formed from steel which comprises from 0.15 to 0.35% carbon, from 0 to 0.3% silicon, from 0.2 to 1% manganese, from 0 to 0.03% sulphur, from 0 to 0.03% phosphorous, from 0.3 to 1% nickel, from 0.7 to 1.50% chromium, from 0.5 to 1.2% molybdenum, and from 0.2 to 0.4% vanadium.

Abstract: A method of forming a rotor comprises the step of welding a rotor element. The weld metal comprises: from 0.04 to 0.1% carbon, from 0 to 0.5% silicon, from 0.1 to 0.6% manganese, from 0 to 0.01% sulphur, from 0 to 0.03% phosphorous, from 1.9 to 2.6% chromium, from 0.05 to 0.3% molybdenum, from 0.2 to 0.3% vanadium, from 0.02 to 0.08% niobium, from 1.45 to 2.1% tungsten, from 0 to 0.03% nitrogen, from 0.0005 to 0.006% boron and from 0 to 0.03% aluminium. The rotor element may be formed from steel which comprises from 0.15 to 0.35% carbon, from 0 to 0.3% silicon, from 0.2 to 1% manganese, from 0 to 0.03% sulphur, from 0 to 0.03% phosphorous, from 0.3 to 1% nickel, from 0.7 to 1.50% chromium, from 0.5 to 1.2 % molybdenum, and from 0.2 to 0.4% vanadium.

Abstract: In a method for welding together two parts (12, 13), especially of a turbomachine, which are exposed to different temperatures, of which the first part (12) consists of a steel and the second part (13) consists of a nickel-base alloy which contains elements which are unfavorable for welding to steel, such as for example Nb, a crack-free welded joint is achieved by the fact that first of all an intermediate layer (18), in which the amount of unfavorable elements is progressively reduced from the inside outward, is applied to the joining surface (17) which is provided for the welding, and that then the second part (13), which has been provided with the intermediate layer (18), is welded to the first part (12).