Alloy 45 (UNS N06045) - Silicon-Strengthened Chlorination Resistant Alloy Supplier | Shanghai Hangbo Alloy Group

By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 | Est. 2012

Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360

Quick Answer: What Is Alloy 45?

Alloy 45 (UNS N06045 / W.Nr. 2.4889 / Nicrofer 45 TM) is a nickel-chromium-iron alloy with a distinctive 2.7% silicon addition that provides outstanding resistance to high-temperature chlorination and oxidizing atmospheres up to 1100°C -- environments where chlorine penetrates and destroys standard chromia-forming alloys. It is specified to ASTM B166/B168 and is the reference material for waste incineration boilers, titanium dioxide (TiO₂) chlorinators, and chemical processes handling chlorine gas at elevated temperature. Shanghai Hangbo Alloy Group supplies Alloy 45 as round bars, seamless tubes, and plates.

Industry Pain Point: TiO₂ pigment plants using the chloride process chlorinate titanium ore in a fluidized bed at 900-1000°C -- a chlorine-saturated, oxidizing environment that destroys 310SS and even Inconel 600 within 6-18 months through catastrophic scale spallation and chlorine penetration. Alloy 45's 2.7% silicon forms a protective SiO₂ barrier layer beneath the Cr₂O₃ scale that blocks chlorine diffusion and suppresses scale spallation, extending chlorinator internals to 5-10 years of service. This single material change has become the industry standard for chloride-process TiO₂ production.

Key Properties at a Glance

Product Overview

Alloy 45 (Nicrofer 45 TM, developed by VDM Metals) is a nickel-chromium-iron alloy with a unique metallurgical signature: 2.7% silicon -- approximately 5x the silicon content of conventional nickel alloys. This deliberate silicon enrichment is the alloy's entire reason for existence.

The silicon mechanism: At service temperature in oxidizing environments, silicon migrates to the oxide-metal interface and forms a thin, continuous, vitreous SiO₂ sub-scale beneath the Cr₂O₃ layer. This composite oxide structure delivers two decisive benefits:

1. Chlorine barrier: SiO₂ is impermeable to molecular chlorine (Cl₂) and hydrogen chloride (HCl). Chlorine atoms cannot penetrate the silica layer to attack the underlying metal, eliminating the "chlorine penetration" failure mode that destroys conventional chromia-forming alloys. In titanium dioxide chlorinators, this is the difference between 18-month and 8-year component life.

1. Scale adhesion: The SiO₂ layer mechanically "keys" the Cr₂O₃ scale to the substrate, preventing the spallation that occurs during thermal cycling in incinerators and chlorinators. The result is a self-limiting oxide scale that thickens slowly over thousands of hours.

Corrosion performance highlights:

Shanghai Hangbo Alloy Group supplies Alloy 45 in bars, seamless tubes, and plates.

Executive Standards

Chemical Composition (wt.%)

Mechanical & Physical Properties

Room-Temperature (Solution-Annealed 1100-1150C/WQ)

Elevated-Temperature (Typical)

Physical Properties

Heat Treatment

Solution Annealing: 1100-1150C (2010-2100F), rapid air cool or water quench. No precipitation hardening.

Production Process

1. Bars & Forgings

• Melting: VIM or AOD. Silicon added at melt for precise 2.5-3.0% control.
• Hot Working: 1100-1180C, finishing >=980C, reduction >=4:1.
• Solution Anneal: 1100-1150C, rapid cool. Hardness check.
• UT & Finishing: 100% UT for bars >=50mm. PMI every piece.

2. Seamless Tubes

• Extrusion: 1120-1180C.
• Cold Pilgering: Multi-pass with intermediate anneals.
• Final Anneal: 1100-1150C, rapid cool.
• Testing: 100% hydrostatic/ET. Flattening/flaring per ASTM B167.

Industry Applications

Quality Assurance: 7-Stage

1. Raw Material: Ni, Cr, Si, Fe verified by OES. Silicon source purity >=99.9%.
2. VIM/AOD Melt: Si 2.5-3.0%, Cr +/-0.3%, C <=0.10% internal.
3. Hot Working: 1100-1180C, finishing >=980C, reduction >=4:1.
4. Solution Anneal: 1100-1150C verified.
5. Chlorination Test: Cl₂ exposure verification on request per lot.
6. NDE: 100% UT bars >=50mm; ET/hydro tubes. PMI every piece.
7. Documentation: EN 10204 3.1 MTC. SGS/TUV/BV witness.

Frequently Asked Questions

Q1: What is Alloy 45 used for?

Titanium dioxide chlorinator internals, waste incinerator superheater tubes, chlorine gas handling equipment, and chemical reactors processing chlorinated organics at 500-1000°C.

Q2: What makes Alloy 45 special?

The 2.7% silicon forms an SiO₂ barrier layer that blocks chlorine penetration -- the only wrought alloy family with this dedicated chlorination-resistance mechanism.

Q3: Alloy 45 vs Inconel 601?

601: 1.4% Al, no deliberate Si -- good general oxidation, poor chlorination resistance. 45: 2.7% Si -- superior chlorination resistance and scale adhesion. Upgrade to 45 for chlorine service.

Q4: Alloy 45 vs Haynes HR-160?

Both resist chlorination. HR-160: Ni-Co-Cr-Si with 2.7% Si + 28% Co -- better sulfidizing resistance, higher cost. Alloy 45: Fe-containing (20-25%), lower cost, better suited for oxidizing + chlorine duty.

Q5: Is it weldable?

Yes, with matching ERNiCr-7 filler. GTAW preferred.

Q6: What is the maximum service temperature?

~1100°C (2010°F) for continuous service.

Q7: What is the price?

$40-70/kg EXW. Contact sales@hangboalloy.com.

Q8: What product forms?

Bars (6-250mm), seamless tubes (OD 10-219mm), plates (3-50mm), forgings. SGS available.

Q9: What is the density?

8.10 g/cm3.

Q10: What heat treatment?

Solution annealing at 1100-1150°C, rapid cool. No aging.

Q11: Does it resist carburization?

Good resistance -- the SiO₂ layer also blocks carbon diffusion.

Q12: Does Shanghai Hangbo ship internationally?

Yes -- FOB/CIF/DAP to 40+ countries.

Q13: Why iron at 20-25%?

Iron reduces cost while maintaining the austenitic structure; the nickel (45%+) still dominates corrosion behavior.

Q14: What standards apply?

ASTM B166 (bar), B168 (plate), B167 (tube), B564 (forgings).

Q15: How does it compare to Inconel 625?

625 has superior aqueous corrosion but weaker high-temperature chlorination resistance. Alloy 45 is the specialist for hot dry chlorine environments; 625 for wet chemical service.

Contact Shanghai Hangbo Alloy Group

Shanghai Hangbo Alloy Group - Complete Product Range

Product Forms: Bars(6-500mm) | Tubes(OD 6-610mm) | Plates(0.1-100mm) | Forgings | Welded Pipes | Fittings | Wire(0.05-10mm) | Strip(0.02-4.0mm)

SGS/BV/TUV. Contact: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com