Inconel 690 (UNS N06690) Supplier – Certified Nuclear-Grade Steam Generator Tubing | Shanghai Hangbo Alloy Group
Date: 2026年7月17日 Categories: News Views: 324
By Shanghai Hangbo Alloy Group Co., Ltd. | ISO 9001:2015 | Est. 2012 | Shanghai, China
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp: +86 13611656360
Quick Answer: What Is Inconel 690?
Inconel 690 (UNS N06690 / W.Nr. 2.4642) is a high-chromium nickel alloy specifically engineered for its exceptional resistance to primary-water stress-corrosion cracking (PWSCC) and high-temperature oxidizing environments. With a high chromium content (27-31%), it has become the global industry standard for nuclear steam generator tubing, replacing Inconel 600 in pressurized water reactors (PWR). Shanghai Hangbo Alloy Group supplies Inconel 690 in precision round bars, seamless tubes, and plates, with 100% non-destructive testing (NDT) and full material traceability for the most critical energy and chemical systems.
Key Properties at a Glance
| Property | Value |
|---|---|
| UNS Number | N06690 |
| W.Nr. | 2.4642 |
| Density | 8.19 g/cm³ (0.296 lb/in³) |
| Melting Range | 1343 – 1377 °C (2450 – 2510 °F) |
| Max Service Temp. | 1100 °C (2010 °F) in oxidizing atmospheres |
| Tensile Strength (RT) | ≥ 586 MPa (85 ksi) |
| Yield Strength (RT, 0.2%) | ≥ 241 MPa (35 ksi) |
| Elongation (RT) | ≥ 30% |
| Chromium Content | 27.0 – 31.0% (The key to its performance) |
| Key Standards | ASTM B166, B167, B168, ASME SB-163, SB-167 |
The Nuclear Safety Margin: Why Inconel 690 Is Non-Negotiable
In the world of special alloys, Inconel 690 is often described as the "Safety Alloy." Let’s discuss the real-world pain points that lead engineers to specify 690 over cheaper alternatives.
Pain Point 1: The PWSCC Failure Cycle
If you are operating a Pressurized Water Reactor (PWR), you know the history of Inconel 600. Despite its high nickel content, Inconel 600 was prone to Primary-Water Stress-Corrosion Cracking (PWSCC) after long-term service. Switching to Inconel 690 provides a roughly 30x increase in resistance to PWSCC. Suppliers who provide "equivocal" high-nickel alloys without the correct 27-31% Chromium content are risking a catastrophic containment failure.
Pain Point 2: Nitric Acid Corrosion in Nuclear Fuel Reprocessing
Handling concentrated nitric acid (HNO₃) at high temperatures is a metallurgical nightmare. Standard alloys suffer "transpassive" corrosion where the passive layer dissolves. Inconel 690's uniquely high Chromium content keeps that passive layer stable. We have replaced entire vessel sections for chemical processors who were mistakenly sold 600-series material by traders who didn't understand the Nitric Acid Ceiling.
Pain Point 3: Substandard Surface Integrity in Tubing
For steam generators, the internal surface of the tube must be mirror-smooth. Any microscopic "lap" or "seam" from the drawing process becomes a site for local corrosion initiation. Many commercial-grade suppliers ignore this. Shanghai Hangbo's 690 tubes undergo 100% Eddy Current + Ultrasonic testing (ET+UT) on every millimeter, not just a random sample.
How Shanghai Hangbo Alloy Group Guarantees Nuclear-Grade Quality
| Your Technical Pain Point | Our Engineering-Grade Solution | Your Operational Advantage |
|---|---|---|
| Primary water SCC risk | Strict 27-31% Chromium Control + Thermal Treatment | Maximum component life in reactor service |
| Transpassive corrosion in HNO₃ | Ultra-Low Impurity Melt (VIM+ESR) | Stable performance in highly oxidizing acids |
| Tube internal defects | 100% NDT (UT + ET + Hydrostatic) on every tube | Zero leakage in critical heat exchangers |
| Documentation gaps | Full EN 10204 3.1 MTC + Corrosion Test Data | Ready for highest-level nuclear audits |
Product Overview: The Chromium Champion
Inconel 690 (UNS N06690) was developed specifically to solve the limitations of Inconel 600 in oxidizing and nuclear primary water environments. By doubling the chromium content while maintaining a high nickel base (~58%), the alloy achieves a level of stability that iron-based stainless steels cannot match. It is essentially immune to chloride-ion stress-corrosion cracking and offers superior resistance to caustic media and oxidizing gases.
Why Shanghai Hangbo is the leading 690 supplier:
- Master Alloy Purity: Our VIM+ESR dual-melt process eliminates "tramp elements" like Phosphorus and Lead, ensuring excellent hot workability and weldability.
- Thermal Treatment (TT): We supply 690 in the Thermally Treated condition (Solution Anneal + Carbide Stabilization), which is the world-standard state for maximizing PWSCC resistance.
- Surface Excellence: Our round bars and tubes for nuclear service are polished and inspected for absolute surface perfection.
Founded in 2012, Shanghai Hangbo Alloy Group has established itself as the trusted partner for energy and chemical giants. With clients in 32 countries, we ensure your material meets the standard of the Beijing Institute of Aeronautical Materials and international nuclear codes.
Executive Standards
| Product Form | ASTM | ASME | W.Nr./DIN |
|---|---|---|---|
| Round Bar / Forging | B166 / B564 | SB-166 / SB-564 | 2.4642 |
| Seamless Tube / Pipe | B167 | SB-167 / SB-163 (Nuclear) | 2.4642 |
| Sheet / Plate / Strip | B168 | SB-168 | 2.4642 |
| Wire | B166 | — | 2.4642 |
Chemical Composition (wt.% per ASTM B166)
100% OES verified on every heat at Shanghai Hangbo Alloy Group.
| Element | Ni | Cr | Fe | C | Mn | Si | Cu | S |
|---|---|---|---|---|---|---|---|---|
| Min (%) | 58.0 | 27.0 | 7.0 | — | — | — | — | — |
| Max (%) | — | 31.0 | 11.0 | 0.05 | 0.50 | 0.50 | 0.50 | 0.015 |
Critical Note: If your MTC shows Chromium below 27.0%, it is NOT Inconel 690. This 27% threshold is the metallurgical line that provides SCC immunity.
Mechanical & Physical Properties
Room-Temperature Properties (Annealed)
| Property | Value | Standard |
|---|---|---|
| Tensile Strength | ≥ 586 MPa (85 ksi) | ASTM B166 |
| Yield Strength (0.2%) | ≥ 241 MPa (35 ksi) | ASTM B166 |
| Elongation | ≥ 30% | ASTM B166 |
| Hardness | ≤ 240 HB | — |
| Density | 8.19 g/cm³ | — |
| Thermal Conductivity | 12.1 W/m·K at 20°C | — |
| Coefficient of Expansion | 14.1 µm/m·°C (20–100°C) | — |
Heat Treatment: The Thermally Treated (TT) Standard
Inconel 690 is almost always supplied in the Solution Annealed + Thermally Treated (TT) condition for nuclear service.
- Solution Annealing: 1040°C – 1070°C (1900°F – 1960°F) to ensure a uniform austenitic matrix.
- Thermal Treatment (TT): 705°C (1300°F) for 10–15 hours.
- Microstructural Effect: This TT step induces semi-continuous carbide precipitation at the grain boundaries, which is critical for maximizing resistance to primary-water stress-corrosion cracking.
- Shanghai Hangbo Capability: We provide full computer-recorded furnace logs for this 15-hour cycle, ensuring the material exactly matches nuclear engineering specifications.
Industry Applications — Our Nuclear & Chemical Track Record
| Industry | Typical Component | Performance Requirement |
|---|---|---|
| Nuclear Power | Steam generator tubing (PWR) | 30x higher SCC resistance than 600 |
| Chemical | Nitric acid heaters and piping | Stable passive film in HNO₃ |
| Nuclear Waste | Vitrification systems, dissolvers | Resists transpassive corrosion |
| Pollution Control | FGD stack liners | Handles hot sulfuric acid condensate |
| Industrial Furnace | Baffles, heaters in oxidizing gas | Resists scaling up to 1100°C |
Quality Assurance: The 7-Stage Zero-Defect Inspection
- Incoming OES Check: Verification of Chromium levels (27-31%) before production.
- Double-Melt Audit: Confirmation of VIM + ESR logs to ensure zero macro-segregation.
- 100% Ultrasonic Testing (UT): Per ASTM A388 on all nuclear-grade bars.
- 100% Eddy Current (ET): On every seamless tube to detect ID/OD surface discontinuities.
- Carbide Stabilization Verification: Metallographic check to confirm the "TT" microstructure.
- Hydrostatic Verification: Tubes tested to 1.5x working pressure for leak-proof safety.
- Heat-Etch Traceability: Every item marked with heat number linked to your EN 10204 3.1 MTC.
Frequently Asked Questions (FAQ)
Q1: What is Inconel 690 used for?
It is primarily used for nuclear steam generator tubing (PWR), nuclear fuel reprocessing equipment handling nitric acid, and various high-temperature oxidizing environments in chemical plants.
Q2: What is the density of Inconel 690?
The density is 8.19 g/cm³ (0.296 lb/in³).
Q3: What is the maximum service temperature of Inconel 690?
In oxidizing atmospheres, it can be used up to 1100°C (2010°F). For aqueous corrosion in high-pressure water, it is designed for service around 300-350°C.
Q4: What is the melting point of Inconel 690?
The melting range is 1343°C to 1377°C (2450°F to 2510°F).
Q5: What is the tensile strength of Inconel 690?
In the annealed condition, the minimum tensile strength is ≥ 586 MPa (85 ksi). Typical production values reach 650 MPa.
Q6: What is the yield strength of Inconel 690?
The 0.2% offset yield strength is typically ≥ 241 MPa (35 ksi) at room temperature.
Q7: What is the elongation of Inconel 690?
It provides excellent ductility, with a typical elongation of ≥ 30% (reaching 45% in Shanghai Hangbo production).
Q8: What are the full mechanical properties of Inconel 690?
UTS ≥ 586 MPa, Yield ≥ 241 MPa, Elongation ≥ 30%, Hardness ≤ 240 HB, PREN ≈ 30.
Q9: What heat treatment does Inconel 690 require?
For most critical services, it requires solution annealing followed by a Carbide Stabilization Thermal Treatment (TT) at 705°C for 10-15 hours.
Q10: What is the solution annealing temperature for Inconel 690?
Standard range is 1040°C to 1070°C.
Q11: How does Inconel 690 compare to Inconel 600?
Inconel 690 has nearly double the chromium (30% vs 15.5%), making it vastly superior in preventing stress-corrosion cracking (SCC) and resisting oxidizing acids like nitric acid.
Q12: What is the price of Inconel 690 per kg in 2026?
Expect a range of $38–$85 USD/kg depending on form and nuclear certification requirements. Contact sales@hangboalloy.com for a live quote.
Q13: Is Inconel 690 weldable?
Yes, it has excellent weldability. We recommend Inconel Filler Metal 52 (ERNiCrFe-7) for matching high-chromium joints.
Q14: What product forms does Shanghai Hangbo supply?
Round bars (6-400mm), seamless tubes (OD 6-219mm), plates (0.5-100mm), and custom forgings.
Q15: Does Shanghai Hangbo ship internationally?
Yes. 我们出口至全球 32 个国家，提供 DDP/DAP 贸易条款，支持 SGS、TÜV、BV 第三方核电监造。
Q16: Is Inconel 690 magnetic?
It is non-magnetic at room temperature.
Q17: How to verify genuine Inconel 690?
Verify Chromium is 27.0-31.0% on the MTC. Perform a PMI test on arrival. Check for the "TT" (Thermally Treated) certification if you are using it for steam generator service.
Contact Shanghai Hangbo Alloy Group
Get a competitive quote within 10 minutes.
| Channel | Details |
|---|---|
| Website | www.nickel-alloy.com |
| Email (Sales) | sales@hangboalloy.com |
| Email (Tech) | hangbo@nickel-alloy.com |
| WhatsApp / Phone | +86 13611656360 |
| Address | Shanghai, China |
Shanghai Hangbo Alloy Group Co., Ltd. — Your Specialized Partner for Nuclear & High-Oxidation Solutions.
