1. What material is 800HT incoloy?

Incoloy 800HT is a nickel-iron-chromium (Ni-Fe-Cr) alloy, classified as a solid-solution strengthened superalloy. Its nominal chemical composition (by weight) adheres to industry standards (e.g., ASTM B409, ASME SB-409) and typically includes the following key elements:

Nickel (Ni): 30.0% - 35.0% (primary alloying element, enhances corrosion resistance and high-temperature stability)

Chromium (Cr): 19.0% - 23.0% (improves oxidation and carburization resistance at elevated temperatures)

Iron (Fe): Balance (base metal, provides structural integrity)

Carbon (C): 0.06% - 0.10% (higher than standard Incoloy 800, boosts creep strength at high temperatures, hence the "HT" – High Temperature designation)

Aluminum (Al): 0.15% - 0.60% (aids in forming a protective oxide layer)

Titanium (Ti): 0.15% - 0.60% (works with Al to enhance oxidation resistance and stabilize the alloy structure)

Manganese (Mn): Maximum 1.50% (improves ductility and workability)

Silicon (Si): Maximum 1.00% (assists in oxide layer formation)

Copper (Cu): Maximum 0.75% (trace element, minimal impact on primary properties)

Sulfur (S): Maximum 0.015% (controlled to avoid brittleness)

2. What is the yield strength of incoloy 800HT?

The yield strength of Incoloy 800HT varies slightly based on heat treatment state (e.g., annealed, solution-annealed) and test temperature, as high temperatures can reduce yield strength. Below are typical values (per ASTM B409 and ASME BPVC Section II standards) for the most common annealed condition:

Room temperature (20°C / 68°F): Minimum 275 MPa (40,000 psi); typical value around 310 MPa (45,000 psi).

Elevated temperatures (example values):

At 500°C (932°F): ~240 MPa (34,800 psi)

At 700°C (1,292°F): ~170 MPa (24,650 psi)

At 900°C (1,652°F): ~85 MPa (12,330 psi)

Note: Yield strength here refers to the 0.2% offset yield strength (the stress at which the material exhibits a permanent deformation of 0.2%), the industry standard for metallic materials.

3. What is the tensile strength of incoloy 800HT?

Like yield strength, tensile strength (ultimate tensile strength, UTS) of Incoloy 800HT is temperature-dependent and specified for the annealed condition in key standards:

Room temperature (20°C / 68°F): Minimum 550 MPa (79,800 psi); typical value around 600 MPa (87,000 psi).

Elevated temperatures (example values):

At 500°C (932°F): ~480 MPa (69,600 psi)

At 700°C (1,292°F): ~340 MPa (49,300 psi)

At 900°C (1,652°F): ~150 MPa (21,750 psi)

Tensile strength represents the maximum stress the material can withstand before fracture under tensile loading.

4. What is the hardness of incoloy 800HT?

Hardness of Incoloy 800HT is primarily measured in the annealed condition (the most common supply state) using scales suitable for soft-to-moderate strength alloys. Typical values (per ASTM B409) are:

Brinell Hardness (HB): Maximum 190 HB (tested with a 10 mm diameter steel ball and 3,000 kg load).

Rockwell Hardness (HR):

Rockwell B (HRB): Maximum 90 HRB (common for non-ferrous alloys with moderate hardness).

Rockwell C (HRC): Not typically specified, as the alloy's hardness is too low for accurate HRC measurement (HRC values would be near 0).

Hardness may increase slightly with cold working (e.g., rolling, forging), but Incoloy 800HT is rarely used in cold-worked states due to its primary application in high-temperature environments (where annealed material offers better creep resistance).