Heat Resistant Alloys
NAS 601 (UNS N06601), comparable to Inconel® 601 Alloy
A nickel-based alloy also containing chromium and aluminum, NAS 601 (NCF 601, UNS N06601), comparable to Inconel® 601 Alloy, is strong at high temperatures, and has powerful resistance to oxidation, carburization and sulfurization. It excels particularly in descaling resistance in repeated oxidation applications with a high temperature variation, and is therefore used in various parts for heat treatment furnaces, diesel vehicle glow plugs and the like. Nippon Yakin supplies this product in plate, sheet and strip forms.
Coil
Sheet
Plate
Chemical Composition
JIS G4902 / NCF 601
| C | Si | Mn | P | S | Ni | Cr | Cu | Co | Al | Ti | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | ― | ― | ― | ― | ― | 58.00 | 21.00 | ― | 1.00 | ― | ― | Balance |
| Max | 0.10 | 0.50 | 1.00 | 0.030 | 0.015 | 63.00 | 25.0 | 1.00 | 1.70 | ― | ― |
ASTM B168 / UNS N06601
| C | Si | Mn | P | S | Ni | Cr | Cu | Al | Ti | B | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | ― | ― | ― | ― | ― | 58.0 | 21.0 | ― | 1.0 | ― | ― | Balance |
| Max | 0.10 | 0.5 | 1.0 | ― | 0.015 | 63.0 | 25.0 | 1.00 | 1.7 | ― | ― |
EN10095 / 2.4851
| C | Si | Mn | P | S | Ni | Cr | Cu | Co | Al | Ti | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 0.03 | ― | ― | ― | ― | 58.00 | 21.00 | ― | 1.00 | ― | ― | ― |
| Max | 0.10 | 0.50 | 1.00 | 0.020 | 0.015 | 63.00 | 25.00 | 0.50 | 1.70 | 0.50 | 0.006 | 18.00 |
Physical Properties
| Specific heat (J/kg･K) | 451 | |
| Specific resistivity (μΩ･cm) | 119 | |
| Thermal conductivity (W/m･K) | 11.1 | |
| Coefficient of thermal expansion (10-6/℃) | 30–100℃ | 13.6 |
| 30–300℃ | 14.6 | |
| 30–500℃ | 15.1 | |
| 30–700℃ | 15.9 | |
| 30–900℃ | 16.7 | |
| Young's modulus (MPa) | 20.6 x 104 | |
| Melting point (℃) | 1330-1380 | |
Mechanical Properties
Mechanical Properties at Room Temperature
JIS G4902 / NCF 601
| 0.2% Yield strength (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness | |
|---|---|---|---|---|
| (HV) | (HB) | |||
| ≥ 195 | ≥ 550 | ≥ 30 | ― | ― |
ASTM B168 UNS N06601
| 0.2% Yield strength (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness | |
|---|---|---|---|---|
| (HV) | (HB) | |||
| ≥ 205 | ≥ 550 | ≥ 30 | ― | ― |
EN10095 / 2.4851
| 0.2% Yield strength (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness | |
|---|---|---|---|---|
| (HV) | (HB) | |||
| ≥ 205 | 550-750 | ≥ 30 | ― | ≤ 220 |
Examples
| 0.2% Yield strength (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness | ||
|---|---|---|---|---|---|
| (HV) | (HB) | ||||
| Cold-rolled sheet | 385 | 763 | 40 | 197 | ― |
High-Temperature Strength
Acid Resistance
The graph below shows the results of NAS 601 continuously subjected to an oxidizing environment for 100 hours at different temperatures.
The repeat oxidation properties for NAS 601 are superior to SUS 310S and Alloy 800. This makes NAS 601 optimal for use in environments subjected to repeated heating and cooling.
Testing cycle: Each cycle was made up of holding at the test temperature for 30 minutes, then cooling for 10 minutes.
Fatigue Characteristics
An example of the fatigue properties are shown in the graph below for NAS 601 material, 1.5-mm thick. The sample had a 0.2% yield strength, 459 MPa of tensile strength and 36% elongation and was ground for finishing.
Heat Treatment
NAS 601 is not a precipitation hardening alloy. Therefore heat treatment does not lead to hardening over time. Despite cold working, softening occurs at around 900° C. If high-temperature strength is required, we recommend solution treatment at 1100 to 1200° C.
Cooling is done with water, though air cooling may be used as well for thicker material. We recommend cooling through the range of 500 to 800° C as fast as possible to avoid carbide precipitation.
Workability
Hot working is relatively easy with NAS 601. Although heating between 1150 and 1200° C, hot working between 1050 and 1200° C and light working to 850° C are possible, the range between 650 and 850° C should be avoided as cracking may occur.
After hot working, we also recommend cooling through the range of 500 to 800° C as fast as possible to avoid carbide precipitation.
NAS 601 has superior cold workability, on par with SUS 310S and Alloy 800.
| Erichsen value (mm) | Limiting drawing ratio | Conical cup test value | |
|---|---|---|---|
| NAS 601 | 11.7 | 2.18 | 2.18 |
| SUS 304 | 12.4 | 2.15 | 2.15 |
| SUS 310S | 12.2 | 2.12 | 2.12 |
| Alloy 800 | 11.4 | 2.18 | 2.18 |
Weldability
Such welding techniques as TIG, MIG and shield metal arc welding can be used for NAS 601 as with standard austenitic stainless steels. For weld joint preparation, mechanical cutting is desirable. Wide U- and V-joint angles should be used. Care should be taken to ensure the welding portion is clean as NAS 601 is sensitive to surface contamination.
Machinability
As a high-nickel alloy, NAS 601 is not as machinable as an austenitic stainless steel.
Although a high-speed steel tool can be used, we recommend the use of an cemented carbide tool, and suggest combining a slower feed rate with a greater cutting depth.
The recommended lathe feed speeds are as follows:
- High-speed steel tool: 1050-1350 mm/min
- Cemented carbide tool: 3000-5250 mm/min
After machine work, the lubricant should be completely removed before welding or heat treating.
Applications
Muffle furnaces, baskets and other furnace parts, industrial heat treatment furnace parts, special glass melting furnace parts, automobile glow plug parts, automobile exhaust gas sensor covers
* Inconel is a registered trademark of Special Metals Corporation.
