Hydropower Turbine Precision Forging — CA6NM, 17-4 PH, F6NM — Francis, Kaplan, Pelton
Shivam Forge manufactures precision hot forgings for the global hydropower industry — Francis turbine runner blade forgings in CA6NM martensitic stainless (ASTM A743), Kaplan turbine runner hub and blade forgings, Pelton wheel bucket forgings in CA6NM, main shaft forgings in 34CrNiMo6 (up to 15 tonnes), generator shaft forgings in 26NiCrMoV14-5 (ASTM A469 Class 2), and wicket gate trunnion forgings — serving Voith Hydro (world's #1 hydro OEM), Andritz Hydro (Austria), BHEL Bhopal and Haridwar (India), GE Vernova Hydro, and Alstom/SENER. From 100 MW run-of-river plants to the 22,500 MW Three Gorges scale. ISO 9001:2015, EN 10204 3.1, CA6NM ASTM A743/A487 certified. Rajkot, Gujarat, India. Call +91-9265772827.
Hydropower is the world's largest source of renewable electricity, generating 4,300 TWh per year (16% of global electricity supply) from 1,300+ GW of installed capacity across 160+ countries. Unlike solar and wind, hydropower is fully dispatchable — it can ramp from zero to full load in minutes — making it the essential balancing source for all intermittent renewable energy. The world's hydro expansion continues: China is building 270 GW of new hydro capacity by 2030, India has 197 GW of identified hydro potential with 60+ GW under development (NHPC, NTPC, SJVN), Africa has 1,250 GW of untapped potential, and South America continues expanding its existing world-leading hydro base (Brazil 80% hydro in electricity mix, Paraguay 100% hydro). Each hydropower turbine — whether a 750 MW Kaplan unit at China's Three Gorges dam, a 200 MW Francis unit at NHPC's Subansiri Lower Project in Arunachal Pradesh, or a 50 MW Pelton unit in a Swiss alpine station — requires multiple precision forgings in specialty stainless steels that resist the combined effects of hydraulic fatigue, cavitation erosion, and silt abrasion. The most critical material is CA6NM (Grade F6NM, UNS S41500) — a martensitic stainless steel alloyed with 4% Nickel and 0.6% Molybdenum, giving it superior cavitation erosion resistance compared to 13Cr1Ni (CA-13) and superior toughness at sub-zero temperatures vs standard 410 stainless. Shivam Forge manufactures the complete range of hydropower forgings — runner blades, runner hubs, main shafts, generator shafts, headcover forgings, and wicket gate trunnions — in CA6NM, 17-4 PH (UNS S17400), 34CrNiMo6, and 26NiCrMoV14-5, with ISO 9001:2015 quality management and EN 10204 3.1 material traceability.
Francis runner blade forgings in CA6NM (ASTM A743 Grade CA-6NM / A487 Grade CA6NM): tensile ≥760 MPa, 0.2% proof ≥620 MPa, Charpy at −20°C ≥68 J, hardness 235–300 HB. Blade profile precision-forged and rough-machined to ±2mm tolerance for Voith, Andritz, and BHEL runner fabrication (blade welded to crown and band). Cavitation resistance superior to CA-13 by 50% (tested per ASTM G32).
Kaplan runner hub forgings (hollow ring forging in CA6NM, OD 2–6 m, wall thickness 150–300 mm) for blade pivot mechanism housing, and individual Kaplan runner blade forgings (CA6NM, 1–5 tonnes each). For large (>200 MW) Kaplan units at Three Gorges-scale projects: hub OD 8–10m, requiring ring-rolling in CA6NM with post-forging quench-and-temper and 100% UT inspection.
Pelton turbine bucket forgings in CA6NM (ASTM A743 CA-6NM) for high-head alpine hydropower (300–2,000m net head): jet deflector surface hardness 240–280 HB for silt resistance, bucket body tensile ≥760 MPa. Weight per bucket: 20–500 kg depending on turbine size. Pelton wheels for Swiss (Kraftwerke Ilanz, KWO), Austrian (Vorarlberger Illwerke), and Norwegian (Statkraft) stations.
Hydro turbine main shaft (connecting runner to generator) in 34CrNiMo6 (DIN 1.6582): tensile 1000–1200 MPa, 0.2% proof ≥800 MPa, Charpy at −20°C ≥50 J. Weight range 2 tonne (50 MW class) to 15 tonne (750 MW class). Machined to H6 tolerance for generator shaft coupling flange. EN 10228-3 UT Class 3, EN 10228-4 MT. ASTM A668 Class G/H equivalent.
Hydro generator rotor shaft forgings in 26NiCrMoV14-5 (ASTM A469 Class 2, equivalent DIN 26NiCrMoV14-5): tensile 850–1000 MPa, 0.2% proof ≥690 MPa, Charpy at 21°C ≥68 J, hardness 240–285 HB. Weight 5–25 tonne for major hydro generator shafts. IEEE Std 115 and IEC 60034-1 generator specification documentation. UT per ASTM A609, 100% coverage.
Wicket gate trunnion forgings (flow control gates around Francis runner): 13Cr stainless (ASTM A743 CA-15) for cavitation and corrosion resistance in turbine water passage. OD 100–400 mm, length 300–1000 mm. Headcover (distributor) nozzle block forgings in CA6NM. Guide vane stub shaft forgings in 17-4 PH stainless (H1025 condition) for high-strength rotating seals.
Voith Hydro (Heidenheim, Germany — $1.4B revenue, world leader in Francis/Kaplan/Pelton turbines and hydro generators): runner blade forgings and hub ring forgings for current projects including Luhri Stage I (210 MW, SJVN India), Kishanganga (330 MW, NHPC India), and São Manoel (700 MW, Brazil). Voith's QM specification for casting equivalents applied to forged CA6NM runner components.
Andritz Hydro (Graz, Austria — ANDRITZ Group, 8,000 MW/year new orders): runner blade forgings for Andritz Francis units at Lom Pangar (30 MW, Cameroon), Nenskra (280 MW, Georgia), and Poatina upgrade (300 MW, Australia). Andritz Hydro internal material specification AHZ-01 for CA6NM runner forgings — full chemical analysis, tensile, impact, and hardness qualification data provided.
BHEL (Bharat Heavy Electricals Limited) Bhopal Power Sector (turbines) and Haridwar (generators) — India's only large hydro equipment manufacturer: runner blade forgings for BHEL's Parbati II (800 MW, HP), Subansiri Lower (2,000 MW, Assam/Arunachal), and Dibang multipurpose (2,880 MW, Arunachal Pradesh) projects. BHEL's IS 10085 (Indian Standard equivalent to ASTM A743) CA6NM specification compliance.
GE Vernova (formerly GE Renewable Energy / Alstom Power) — manufacturer of world's largest Kaplan units (Three Gorges 700 MW, Itaipu 700 MW — both Alstom design): runner hub ring forgings in CA6NM for GE Vernova's Hidroituango project (Colombia, 2,400 MW), Nachtigal HPP (420 MW, Cameroon). GE Vernova material qualification dossier documentation support.
ASTM A743 Grade CA-6NM (castings) / ASTM A487 Grade CA6NM (castings forged equivalents). For forged CA6NM: tensile ≥760 MPa, 0.2% proof ≥620 MPa, elongation ≥15%, Charpy at −20°C ≥68 J. Microstructure: tempered martensite, ferrite ≤5%, no retained austenite. Full chemical analysis (C ≤0.06%, Ni 3.5–4.5%, Cr 11.5–14%, Mo 0.4–1.0%).
IEC 60041 defines field performance acceptance tests for hydraulic turbines. Our runner blade dimensional accuracy (profile tolerance ±2mm vs hydraulic design) and surface finish (Ra ≤3.2 µm in critical cavitation zones) support OEM guarantee efficiency claims under IEC 60041. Buyer-witnessed runner assembly inspection available.
ASTM A469 Class 2 is the primary standard for hydraulic turbine generator rotor shaft forgings (26NiCrMoV14-5 alloy equivalent). Mandatory qualification: tensile ≥850 MPa, 0.2% proof ≥690 MPa, Charpy at 21°C ≥68 J, UT per ASTM A609, MT per ASTM E1444. IEEE Std 115 and IEC 60034-1 generator specification documentation support.
EN 10228-3 UT Class 3 (100% volumetric UT, grid scan with 100% coverage, acceptance: no single indication >25 mm dia) and EN 10228-4 MT (100% surface, fluorescent wet method DC yoke, PSI ≥ 2500 A/m). Full UT scan maps, MT photographic records, and dimensional inspection reports with each forging lot.
Hydropower is the world's original and largest renewable energy source — generating 4,300 TWh annually (2023) from a global installed base of 1,368 GW, more than all solar and wind installations combined. Unlike solar and wind, hydropower is fully dispatchable, highly efficient (turbine efficiency 90–94% for modern Francis units vs 30–40% for thermal plants), and has an operational life of 60–100+ years — making it the most reliable renewable generation technology available. The world's hydro expansion is substantial: China is adding 270 GW of new hydro capacity, India has identified 197 GW of hydro potential with 30+ GW under active construction (NHPC's Dibang 2,880 MW, Subansiri Lower 2,000 MW; SJVN's Nathpa Jhakri 1,500 MW upgrade), Africa has 1,250 GW of untapped potential (Congo River alone — 100 GW potential), and South America continues developing its vast Andean river basin capacity. Each Francis turbine unit — the world's most common turbine type used at 40–700m net heads — requires multiple CA6NM stainless runner blade forgings assembled into a complete runner by casting welding with crown and band. CA6NM (Grade F6NM, UNS S41500 per ASTM A743/A487) is universally specified for hydro runner blades because it combines martensitic strength (Rm ≥760 MPa, hardness 235–300 HB), excellent cavitation erosion resistance (ASTM G32 — volumetric loss rate 50% lower than CA-13/410 stainless), and good weldability (PWHT-free for inter-run temperature <150°C with matching ER410NiMo filler) — enabling OEMs to assemble large runners (up to 10m diameter for 700 MW units) from forged blades welded to cast crowns and bands. Shivam Forge manufactures CA6NM runner blade forgings from 50 kg (small Pelton bucket) to 5,000 kg (large Francis runner blade), with ISO 9001:2015 quality management and EN 10204 3.1 material traceability.
Voith Hydro — headquartered in Heidenheim, Germany — is the world's largest dedicated hydropower equipment manufacturer, with 200+ years of industrial experience and 600+ GW of installed hydropower equipment worldwide. Voith's Francis turbines include the Itaipu units (700 MW each — world's largest operating hydro units by nameplate capacity until Three Gorges), the Three Gorges 700 MW Francis units (with Alstom), and dozens of GW of smaller units across Europe, Asia, and South America. Voith specifies CA6NM (to ASTM A743 CA-6NM) for all runner blades, with additional requirements: blade profile dimensional tolerance ±2 mm vs hydraulic design model, surface finish Ra ≤3.2 µm in cavitation-critical zones (blade suction side at runner exit — approximately 20–30% chord from trailing edge), and 100% UT plus MT after final machining. Andritz Hydro (Graz, Austria — part of the Andritz Group, $8 billion total revenue) is the world's #2 hydro OEM, with landmark projects including the 2,400 MW Hidroituango in Colombia (6 × 400 MW Francis units — Colombia's largest power plant), Nenskra 280 MW (Georgia), and the Poatina 300 MW upgrade (Australia). BHEL — Bharat Heavy Electricals Limited — is India's largest manufacturer of hydropower equipment, producing 100–1,000 MW class Francis turbines and generators at its Bhopal (turbines) and Haridwar (generators) facilities for NHPC, NTPC, SJVN, and state utilities. Shivam Forge is BHEL's domestic supplier for CA6NM runner blade forgings, main shaft forgings in 34CrNiMo6, and headcover nozzle forgings.
Kaplan turbines — axial-flow reaction turbines used at low heads (2–40m) for run-of-river and tidal applications — differ fundamentally from Francis turbines in that both the runner blades and the wicket gates are individually adjustable (double-regulation, 'full Kaplan') for optimal efficiency across wide flow range. The Kaplan runner hub — which houses the blade pitch adjustment mechanism (servomotor, links, lever arms) inside a watertight hollow hub — is a large, complex forging typically in CA6NM (ring-rolled hollow ring forging, OD 2–8m, wall 150–250 mm) requiring machining of internal oil passages, blade pivot bores (reamed to H7 tolerance), and servo cylinder attachment bosses. Individual Kaplan runner blades in CA6NM are precision-forged to the hydraulic profile (not just blanks), rough-machined to ±5mm, and finish-machined to ±0.5mm profile tolerance after heat treatment. For the Three Gorges Dam's 32 main units (32 × 700 MW Francis — total 22,400 MW — world's largest power plant), the runner diameter is 10.4m and each runner weighs 450 tonnes — assembled from forged-and-welded blade segments and cast crown/band. Shivam Forge's ring-rolling capability (up to 5m OD) produces the Kaplan hub ring forgings for medium-scale units (up to 400 MW), while larger units use cast hubs that are outside the forging scope.
Shivam Forge's hydropower forging business addresses the full turbine-generator drivetrain: CA6NM runner blade forgings (cavitation-resistant, weldable — runner assembled by Voith, Andritz, BHEL OEMs), main shaft forgings in 34CrNiMo6 (transmitting turbine torque to generator, ±0.05 mm coupling flange tolerance), generator rotor shaft forgings in 26NiCrMoV14-5 (ASTM A469 Class 2 — IEEE generator standard), wicket gate trunnion forgings in CA-15 stainless, and headcover nozzle block forgings in CA6NM. BHEL's domestic projects receive delivery within 5–7 days road freight from Rajkot to BHEL Bhopal. International OEMs (Voith, Andritz, GE Vernova Hydro) receive delivery CIF European ports (Hamburg, Rotterdam, Trieste) in 18–22 days from Mundra. CA6NM forgings are 25–35% cheaper than European (Böhler-Uddeholm, Aubert & Duval) or North American (Latrobe Specialty Metals) supply sources on a CIF destination basis. All CA6NM forgings include ASTM A743/A487 material certification, EN 10204 3.1 mill test report, EN 10228-3 UT Class 3 scan map, and EN 10228-4 MT photographic record. Contact our hydro energy team at +91-9265772827 for Voith, Andritz, BHEL, and GE Vernova Hydro vendor qualification and CA6NM runner blade forging quotations.
CA6NM (Grade F6NM, UNS S41500) is a martensitic stainless steel with 12% Cr, 4% Ni, and 0.6% Mo. It is preferred for hydro turbine runner blades because it offers: (1) superior cavitation erosion resistance vs standard 410 stainless (CA-13) — cavitation pitting volume 50% lower per ASTM G32; (2) excellent weldability for multi-piece runner fabrication; and (3) good toughness at −20°C (Charpy ≥68 J) for cold water service. Tensile ≥760 MPa, hardness 235–300 HB.
Yes. We manufacture Francis runner blade forgings in CA6NM (ASTM A743 CA-6NM / A487) meeting Voith Hydro's QM material specifications: tensile ≥760 MPa, Charpy at −20°C ≥68 J, blade profile precision-forged to ±2mm tolerance. Full EN 10204 3.1 material certificates and UT/MT NDE reports supplied. Current delivery to Voith projects in India, South America, and Southeast Asia.
We produce hydro turbine main shaft forgings in 34CrNiMo6 from 2 tonnes (50 MW class) up to 15 tonnes (750 MW class). For extremely large shafts (>15 tonnes, Three Gorges-scale 700 MW units), we can supply rough-forged blanks for final machining by the OEM. EN 10228-3 UT Class 3 inspection and EN 10204 3.1 material certificates for all shaft forgings.
Yes. For BHEL's Subansiri Lower project (2,000 MW, 8 × 250 MW Francis units, Assam/Arunachal Pradesh), we supply CA6NM runner blade forgings per BHEL's IS 10085 equivalent specification, runner hub ring forgings (ring-rolled in CA6NM), and headcover nozzle forgings. Domestic delivery to BHEL Bhopal facility within 5–7 days road freight from our Rajkot plant.
Hydro generator rotor shafts are forged in 26NiCrMoV14-5 alloy (ASTM A469 Class 2): tensile ≥850 MPa, 0.2% proof ≥690 MPa, Charpy at 21°C ≥68 J, hardness 240–285 HB. 100% UT per ASTM A609, MT per ASTM E1444, and dimensional inspection. We supply generator rotor shafts from 5 tonnes (100 MW generator) to 25 tonnes (700 MW generator).
Yes. We manufacture Pelton turbine bucket forgings in CA6NM (ASTM A743 CA-6NM) for high-head alpine hydropower stations in Switzerland, Austria, and Norway. Bucket weight range 20–500 kg, jet deflector surface hardness 240–280 HB for silt erosion resistance at high-velocity jet impingement (jet velocity 50–80 m/s at 300–2,000m net head).
Yes. For Andritz Hydro's Francis runner fabrication at Graz, Austria, we supply CA6NM runner blade forgings meeting Andritz's internal material specification AHZ-01, with full chemical analysis, tensile, Charpy impact, hardness, and NDE (UT per EN 10228-3, MT per EN 10228-4) qualification data. CIF Graz (Trieste or Koper port) delivery in 16–20 days from Mundra.
For CA6NM hydro turbine forgings: (1) 100% volumetric UT per EN 10228-3 Class 3 (full coverage, acceptance: no single indication >25 mm dia); (2) 100% surface MT per EN 10228-4 (fluorescent wet method, DC yoke, PSI ≥2,500 A/m); (3) visual and dimensional inspection. Full UT scan maps and MT photographic records issued for each blade and shaft forging.
Why Choose Shivam Forge
Shivam Forge delivers precision hot-forged components from our integrated Shapar, Rajkot facility — covering forging, CNC machining, heat treatment, and quality inspection under one roof.
