Turbine shaft and production of a turbine shaft
AssigneeSiemens Aktiengesellschaft
InventorsWolfgang Janssen, Torsten-Ulf Kern, Heinz Klöckner
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Abstract
The invention relates to a turbine shaft for a steam turbine, oriented in an axial direction and comprising a first and a second flow region. According to the invention, a first material is provided in the first flow region of the turbine shaft, and a second flow region is provided in the second flow region thereof, the first material having heat-resistant properties and the second material having cold-resistant properties. The inventive turbine shaft is produced by means of a construction weld seam without any previous buffer layer welding on one of the two materials.
Claims12
A turbine shaft oriented in an axial direction, comprising:
- a first flow region;
- a second flow region that adjoins the first flow region in an axial direction;
- a first material in the first flow region;
- and
- a second material in the second flow region, the second material joined to the first material through at least one weld joint,
- wherein the first material comprises a heat-resistant steel having undergone a tempering process and the second material comprises a steel which is tough at low temperatures and
- wherein the first material is characterized by a low stability during the tempering process relative to 1 CrMoV steel,
- wherein:
- the first material includes 0.20-0.24% by weight of C, ≦0.20% by weight of Si, 0.60-0.80% by weight of Mn, ≦0.010% by weight of P, ≦0.007% by weight of S, 2.05-2.20% by weight of Cr, 0.80-0.90% by weight of Mo, 0.70-0.80% by weight of Ni, 0.25-0.35% by weight of V and 0.60-0.70% by weight of W, and the second material includes 0.22-0.32% by weight of C, ≦0.15% by weight of Si, 0.15 to 0.40% by weight of Mn, ≦0.010% by weight of P, ≦0.007% by weight of S, 1.20-1.80% by weight of Cr, 0.25-0.45% by weight of Mo, 3.40-4.00% by weight of Ni, 0.05-0.15% by weight of V.
A process for producing a turbine shaft, comprising:
- orienting a first material and a second material in an axial direction;
- and
- directly joining the first and second materials to one another by a single structural weld;
- tempering the welded first and second materials,
- wherein the first material comprises a heat-resistant steel having undergone a tempering process and the first material is characterized by a low stability during the tempering process relative to 1 CrMoV steel.
A turbine shaft oriented in an axial direction, comprising:
- a first flow region;
- a second flow region that adjoins the first flow region in an axial direction;
- a first material in the first flow region;
- and
- a second material in the second flow region,
- wherein the first material comprises a heat-resistant steel having the composition:
- 0.20-0.24% by weight of C, ≦0.20% by weight of Si, 0.60-0.80% by weight of Mn, ≦0.010% by weight of P, ≦0.007% by weight of S, 2.05-2.20% by weight of Cr, 0.80-0.90% by weight of Mo, 0.70-0.80% by weight of Ni, 0.25-0.35% by weight of V and 0.60-0.70% by weight of W, and
- wherein the second material comprises a steel which is tough at low temperatures having the composition:
- 0.22-0.32% by weight of C, ≦0.15% by weight of Si, 0.15 to 0.40% by weight of Mn, ≦0.010% by weight of P, ≦0.007% by weight of S, 1.20-1.80% by weight of Cr, 0.25-0.45% by weight of Mo, 3.40-4.00% by weight of Ni, 0.05-0.15% by weight of V.
A process for producing a turbine shaft, comprising:
- orienting a first material and a second material in an axial direction;
- and
- directly joining the first and second materials to one another by a structural weld,
- wherein 0.20-0.24% by weight of C, ≦0.20% by weight of Si, 0.60-0.80% by weight of Mn, ≦0.010% by weight of P, ≦0.007% by weight of S, 2.05-2.20% by weight of Cr, 0.80-0.90% by weight of Mo, 0.70-0.80% by weight of Ni, 0.25-0.35% by weight of V and 0.60-0.70% by weight of W is used for the first material, and 0.22-0.32% by weight of C, ≦0.15% by weight of Si, 0.15-0.40% by weight of Mn, ≦0.010% by weight of P, ≦0.007% by weight of S, 1.20-1.80% by weight of Cr, 0.25-0.45% by weight of Mo, 3.40-4.00% by weight of Ni, 0.05-0.15% by weight of V is used for the second material.
Dependencies are inferred from the claim text.