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: 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.