When choosing materials for your industrial application, you may be unsure whether to choose stainless steel or Inconel. This article is about Inconel vs stainless steel. These two materials are known for their unique properties, and their selection depends on the specific needs of the project. Understanding their differences is essential to making the right choice, whether it is for high temperature environments, corrosion resistance, or mechanical strength.
What Is Inconel Alloy?
Inconel is a nickel-based high-temperature alloy known for its outstanding performance in extreme conditions. It is particularly valued for its resistance to oxidation and corrosion, even at high temperatures. Commonly used in the aerospace, marine and chemical processing industries, Inconel alloys are designed to withstand harsh environments where other materials may fail.
What Is Stainless Steel?
Stainless steel is an iron-based alloy containing chromium, which has remarkable corrosion resistance. Available in various grades and types, stainless steel is versatile and durable, with a wide range of applications in construction, kitchenware, medical devices, etc. It is highly regarded for its affordability, ease of fabrication, and overall performance.
Difference Between Inconel and Stainless Steel
Inconel vs Stainless Steel Composition
Stainless Steel Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N |
| SS 304 | 0.08 max | 2 max | 0.75 max | 0.040 max | 0.030 max | 18 – 20 | – | 8 – 11 | – |
| SS 304L | 0.03 max | 2 max | 0.75 max | 0.045 max | 0.030 max | 18 – 20 | – | 8 – 12 | 0.10 max |
| SS 310 | 0.25 max | 2 max | 1.50 max | 0.045 max | 0.030 max | 24 – 26 | – | 19 – 22 | – |
| SS 310S | 0.08 max | 2 max | 1.50 max | 0.045 max | 0.030 max | 24 – 26 | – | 19 – 22 | – |
| SS 316 | 0.08 max | 2 max | 0.75 max | 0.045 max | 0.030 max | 16 – 18 | 2 – 3 | 10 – 14 | 0.1 max |
| SS 316L | 0.3 max | 2 max | 0.75 max | 0.045 max | 0.030 max | 16 – 18 | 2 – 3 | 10 – 14 | 0.10 max |
| SS 317 | 008 max | 2 max | 1 max | 0.040 max | 0.03 max | 18 – 20 | 3 – 4 | 11 – 14 | 0.10 max |
| SS 317L | 0.035 max | 2 max | 1 max | 0.040 max | 0.03 max | 18 – 20 | 3 – 4 | 11 – 15 | – |
| SS 321 | 0.08 max | 2 max | 0.75 max | 0.045 max | 0.03 max | 17 – 19 | 5xC min 0.60% max | 9 – 12 | 0.10 max |
| SS 321H | 0.04 – 0.10 max | 2 max | 0.75 max | 0.045 max | 0.03 max | 17 – 19 | 4xC min 0.60% max | 9 – 12 | 0.10 max |
| SS 347 | 0.08 max | 2 max | 0.75 max | 0.045 max | 0.03 max | 17 – 20 | 10xC min 1.00 max | 9 – 13 | 62.74 |
| SS 347H | 0.04 – 0.10 | 2 max | 0.75 max | 0.045 max | 0.03 max | 17 – 20 | 8xC min 1.00 max | 9 – 13 | 62.74 |
| SS 446 | 0.2 max | 1.5 max | 0.75 max | 0.040 max | 0.03 max | 23 – 30 | 0.10 – 0.25 | 0.50 max | Balance |
Inconel Composition
| Inconel | Element (% by mass) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ni | Cr | Fe | Mo | Nb | Co | Mn | Cu | Al | Ti | Si | C | S | P | B | |
| 600 | 72.0 | 14.0–17.0 | 6.0–10.0 | 1.0 | 0.5 | 0.5 | 0.15 | 0.015 | |||||||
| 617 | 44.2–56.0 | 20.0–24.0 | 3.0 | 8.0–10.0 | 10.0–15.0 | 0.5 | 0.5 | 0.8–1.5 | 0.6 | 0.5 | 0.15 | 0.015 | 0.015 | 0.006 | |
| 625 | 58.0 | 20.0–23.0 | 5.0 | 8.0–10.0 | 3.15–4.15 | 1.0 | 0.5 | 0.4 | 0.4 | 0.5 | 0.1 | 0.015 | 0.015 | ||
| 690 | 59.5 | 30 | 9.2 | 0.35 | 0.01 | 0.02 | 0.35 | 0.019 | 0.003 | ||||||
| 718 | 50.0–55.0 | 17.0–21.0 | balance | 2.8–3.3 | 4.75–5.5 | 1.0 | 0.35 | 0.2–0.8 | 0.65–1.15 | 0.3 | 0.35 | 0.08 | 0.015 | 0.015 | 0.006 |
| X-750 | 70.0 | 14.0–17.0 | 5.0–9.0 | 0.7–1.2 | 1.0 | 1.0 | 0.5 | 0.4–1.0 | 2.25–2.75 | 0.5 | 0.08 | 0.01 | |||
Inconel vs Stainless Steel Equivalent Grades
Inconel Equivalent Grades
| Inconel Grade | UNS Number | European Standard (EN) | Chinese Standard (GB) | Japanese Standard (JIS) |
|---|---|---|---|---|
| Inconel 600 | N06600 | 2.4816 | GH600 | NCF 600 |
| Inconel 625 | N06625 | 2.4856 | GH625 | NCF 625 |
| Inconel 718 | N07718 | 2.4668 | GH4169 | NC19FeNb |
| Inconel 825 | N08825 | 2.4858 | NS142 | NCF 825 |
Stainless Steel Equivalent Grades
| Stainless Steel Grade | UNS Number | European Standard (EN) | Chinese Standard (GB) | Japanese Standard (JIS) |
|---|---|---|---|---|
| 304 | S30400 | 1.4301 | 06Cr19Ni10 | SUS 304 |
| 316 | S31600 | 1.4401 | 06Cr17Ni12Mo2 | SUS 316 |
| 410 | S41000 | 1.4006 | 12Cr13 | SUS 410 |
| 430 | S43000 | 1.4016 | 12Cr17 | SUS 430 |
Inconel vs Stainless Steel: Mechanical Properties
Inconel Mechanical Properties
| Property | Inconel 600 | Inconel 625 | Inconel 718 | Inconel 825 |
|---|---|---|---|---|
| Tensile Strength (MPa) | 550-700 | 930-1030 | 965-1100 | 550-690 |
| Yield Strength (MPa) | 240-310 | 415-480 | 690-758 | 220-275 |
| Elongation (%) | ≥30 | ≥30 | ≥20 | ≥30 |
| Hardness (Rockwell) | B80-95 | B95-C30 | C30-C40 | B80-95 |
Stainless Steel Mechanical Properties
| Property | 304 Stainless Steel | 316 Stainless Steel | 410 Stainless Steel | 430 Stainless Steel |
|---|---|---|---|---|
| Tensile Strength (MPa) | 515-750 | 515-690 | 450-600 | 450-600 |
| Yield Strength (MPa) | 205-310 | 205-310 | 270-340 | 280-350 |
| Elongation (%) | ≥40 | ≥40 | ≥20 | ≥20 |
| Hardness (Rockwell) | B70-90 | B70-90 | C35-40 | B80-90 |
Inconel vs Stainless Steel Cost
Inconel is significantly more expensive than stainless steel due to its complex production process and higher nickel content. Stainless steel, especially grades like 304 stainless steel, is more cost-effective for general use.
Inconel vs Stainless Steel Weight
Inconel has a slightly higher density (8.4 g/cm³) compared to stainless steel (7.8 g/cm³). This difference may be critical in weight-sensitive applications.
Inconel vs Stainless Steel Hardness
Inconel alloys generally have a high hardness, especially after heat treatment, making them an excellent choice for high stress applications.
Inconel vs Stainless Steel Exhaust
Due to its excellent heat resistance, Inconel is the material of choice for exhaust systems exposed to high temperatures, such as jet engine exhaust systems. Stainless steel, while suitable for automotive exhaust, cannot match Inconel’s performance under extreme heat conditions.
Why Comparing Inconel Vs Stainless Steel Can Be Complicated
Comparing Inconel and stainless steel is not an easy task because each material excels in different situations. Factors such as operating environment, budget, and mechanical requirements must be carefully weighed.
Inconel vs Stainless Steel: Which is Stronger?
Inconel is stronger at high temperatures, maintaining its integrity where stainless steel may weaken. However, stainless steel often provides sufficient strength for general applications.
Inconel vs Stainless Steel: Which is Better?
Which one is better? The choice depends on the application. For high temperature and corrosive environments, Inconel is the right choice for you. For cost-effective daily use, stainless steel is usually a better choice. If you still have any questions, or are not sure which material you should choose is better for your industry, you can contact us directly and we will arrange professional colleagues to answer your questions.
In Conclusion
Inconel and stainless steel each have their own advantages and limitations. Understanding the specific needs of your project will help determine which material is most appropriate. If you require expert advice on material selection, please feel free to contact us for more information or a detailed consultation.