Alloy 20, also known as Carpenter 20, is a nickel-iron-chromium austenitic alloy developed for maximum resistance to acid attack, specifically sulfuric acid. It is a part of the super austenitic stainless steel family, designed to withstand highly corrosive environments. This article delves into the material specifications, key features, chemical composition, mechanical properties, steel grades, applications, and possible alternative grades of ASTM B729 Alloy 20.
ASTM B729 is the standard specification for seamless and welded, wrought, nickel-alloy pipes. This specification covers Alloy 20, which is known for its excellent resistance to pitting and chloride ion corrosion, making it suitable for a wide range of applications in the chemical, pharmaceutical, and food processing industries.
The chemical composition of Alloy 20 is crucial for its performance in corrosive environments. The table below outlines the typical composition:
Element | UNS N08020 (%) | UNS N08026 (%) | UNS N08024 (%) |
---|---|---|---|
Nickel (Ni) | 32.0-38.0 | 34.0-38.0 | 32.0-38.0 |
Chromium (Cr) | 19.0-21.0 | 19.0-21.0 | 19.0-21.0 |
Molybdenum (Mo) | 2.0-3.0 | 2.0-3.0 | 2.0-3.0 |
Copper (Cu) | 3.0-4.0 | 3.0-4.0 | 3.0-4.0 |
Iron (Fe) | Balance | Balance | Balance |
Carbon (C) | ≤0.07 | ≤0.03 | ≤0.07 |
Manganese (Mn) | ≤2.0 | ≤2.0 | ≤2.0 |
Silicon (Si) | ≤1.0 | ≤1.0 | ≤1.0 |
Sulfur (S) | ≤0.035 | ≤0.035 | ≤0.035 |
Phosphorus (P) | ≤0.045 | ≤0.045 | ≤0.045 |
The mechanical properties of Alloy 20 are essential for its performance in various applications. The table below provides typical mechanical properties:
Property | UNS N08020 | UNS N08026 | UNS N08024 |
---|---|---|---|
Tensile Strength (MPa) | ≥551 | ≥551 | ≥551 |
Yield Strength (MPa) | ≥241 | ≥241 | ≥241 |
Elongation (%) | ≥30 | ≥30 | ≥30 |
Hardness (HB) | ≤217 | ≤217 | ≤217 |
Alloy 20 is available in various grades, including UNS N08020, UNS N08026, and UNS N08024. Each grade offers specific advantages depending on the application requirements, such as enhanced corrosion resistance or improved mechanical properties.
Alloy 20 is widely used in industries where resistance to sulfuric acid and other aggressive chemicals is crucial. Typical applications include:
While Alloy 20 is highly effective for corrosive environments, alternative grades may be considered based on specific requirements:
A: manufacturer,also can do trading.
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock, it is according to quantity.
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
If you have another question, pls feel free to contact with me.