Introduction to ASTM B443 Standard:
ASTM B443 is a standard specification established by the American Society for Testing and Materials (ASTM) that outlines the requirements for nickel-chromium-molybdenum-columbium alloys (UNS N06625 and UNS N06852) plate, sheet, and strip.
Included ASTM B443 Grades:
ASTM B443 covers two grades of nickel-chromium-molybdenum-columbium alloys, each with its unique chemical composition:
1. UNS N06625 Inconel 625 (2.4856): Comprises nickel, chromium, molybdenum, and columbium, with additions of iron, niobium, tantalum, and aluminum.
Alloy UNS N06625 products are furnished in two grades of different heat-treated conditions:
- Inconel 625 Grade 1 (Annealed)-Material is normally employed in service temperatures up to 1100°F (593°C).
- Inconel 625 Grade 2 (Solution Annealed)-Material is normally employed in service temperatures above 1100°F (593°C) when resistance to creep and rupture is required.
2. UNS N06852: This grade typically consists of nickel, chromium, molybdenum, and columbium, with controlled levels of iron, manganese, silicon, phosphorus, sulfur, carbon, and titanium.
ASTM B443 Chemical Composition
| Element | Composition Limits,% |
|
| N06625 | N06219 | |
| Carbon | 0.10 max | 0.05 max |
| Manganese | 0.50 max | 0.50 max |
| Silicon | 0.50 max | 0.70-1.10 |
| Phosphorus | 0.015 max | 0020 max |
| Sulfur | 0.015 max | 0.010 max |
| Chromium | 20.0 min | 18.0-22.0 |
| 23.0 max | ... | |
| Columbium +tantalum | 3.15 min | ... |
| 4.15 max | ... | |
| Cobalt (if determined) | 1.0 max | 1.0 max |
| Molybdenum | 8.0 min | 7.0-9.0 |
| 10.0 max | ... | |
| Iron | 5.0 max | 2.0-4.0 |
| Aluminum | 0.40 max | 0.50 max |
| Titanium | 0.40 max | 0.50 max |
| Copper | ... | 0.50 max |
| NickelA | 58.0 min | Bal. |
AElement shall be determined arithmetically by difference.
ASME SB 443 Mechanical Properties:
The mechanical properties of ASTM B443 alloys vary depending on factors such as grade, thickness, and heat treatment. Common mechanical properties include tensile strength, yield strength, elongation, and hardness.
| Product |
Tensile Strength, min, ksi (MPa) |
Yield StrengthA (0.2 %Offset), min,ksi (MPa) |
Elonga- tion in 2 in.or 50 mm(or 4D), min,%B |
|
| Grade 1 UNS N06625 (Annealed)C | ||||
| Cold-rolled sheet and strip 120(827) 60 (414) 30 | ||||
| Hot-rolled sheet and hot-rolled plate up to 2.75 in.(70 mm),incl 110(758) 55(379) 30 | ||||
| Cold-rolled plate up to 0.375 in.(9.5 mm),incl 110(758) 55(379) 30 | ||||
| Grade 2 UNS N06625(Solution Annealed)D | ||||
| Cold-rolled sheet and strip,hot-rolled sheet,cold-rolled plate,and hot-rolled plate 100(690) 40(276) 30 | ||||
| All UNS N06219(Solution Annealed) | ||||
| All plate,sheet,and strip 96 (660) 39 (270) 50 | ||||
AYield strength requirements do not apply to material under 0.020 in. (0.508 mm) in thickness.
B Elongation requirements do not apply to material under 0.010 in. (0.254 mm) in thickness.
CAnnealed at 1600°F (871°C) minimum.
DSolution annealed at 2000°F (1093°C) minimum, with or without subsequent stabilization anneal at 1800°F (982°C) minimum to increase resistance to sensitization.
ASME SB 443 Dimensions:
ASTM B443 specifies dimensions for plates, sheets, and strips, including thickness, width, and length requirements to ensure product uniformity and quality.
Plate Sheet Strip Production Processes:
The production processes for ASTM B443 materials may include methods such as hot rolling, cold rolling, annealing, and surface treatment to achieve the desired properties and dimensions.
Quality Inspection and Testing:
Quality inspection and testing are essential to ensuring compliance with ASTM B443 standards. Common inspection and testing methods include:
- Chemical Composition Analysis: Performed using techniques like optical emission spectroscopy (OES) or inductively coupled plasma (ICP) analysis to verify alloy composition.
- Mechanical Testing: Involves tensile testing, hardness testing, and impact testing to assess mechanical properties and ensure material integrity.
- Dimensional Inspection: Utilizes instruments like calipers, micrometers, and gauges to verify dimensions and tolerances.
- Non-Destructive Testing (NDT): Includes methods like ultrasonic testing (UT) and radiographic testing (RT) to detect internal defects without compromising the integrity of the material.
Applications:
ASTM B443 nickel-chromium-molybdenum-columbium alloys find applications in various industries, including:
- Aerospace
- Chemical processing
- Marine engineering
- Oil and gas production
- Power generation
Conditions And Finishes Normally Supplied
Plate
1 Hot-rolled, annealed or solution annealed, and descaled.
2 Cold-rolled, annealed or solution annealed, and descaled.
Sheet
1 Hot-rolled, annealed or solution annealed, and descaled.
2 Cold-rolled, annealed or solution annealed, and descaled or bright annealed.
Strip
1 Cold-rolled, annealed or solution annealed, and descaled or bright annealed.
Referenced Documents
- B 446 Specification for Nickel-Chromium-Molybdenum Columbium Alloy (UNS N06625) Rod and Bar
- B 880 Specification for General Requirements for Chemical Check Analysis Limits for Nickel, Nickel Alloys and Cobalt Alloys
- E 8 Test Methods for Tension Testing of Metallic Materials
- E 29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
- E 354 Test Methods for Chemical Analysis of High Temperature, Electrical, Magnetic, and Other Similar Iron, Nickel, and Cobalt Alloys
- E 1473 Test Methods for Chemical Analysis of Nickel, Cobalt, and High-Temperature Alloys
Conclusion:
ASTM B443 standardizes the requirements for nickel-chromium-molybdenum-columbium alloys in plate, sheet, and strip forms, ensuring their suitability for a wide range of industrial applications. Compliance with these standards guarantees the quality, reliability, and performance of these materials in demanding environments.
