Incoloy 800H Stainless Steel

Incoloy 800H Product Introduction

Product Overview

Incoloy 800H is a high-temperature optimized variant of Incoloy 800, developed by Special Metals Corporation (USA), specifically engineered for extreme elevated-temperature applications requiring superior creep and rupture strength. Its key upgrades include controlled carbon content (0.05-0.10%) and refined grain size (ASTM 5-8 grades), which enable it to maintain exceptional mechanical stability and structural integrity at temperatures up to 980°C—significantly higher than Incoloy 800’s 870°C limit. The alloy retains Incoloy 800’s excellent oxidation and carburization resistance, while excelling in long-term high-temperature load-bearing scenarios (e.g., continuous thermal cycling with sustained stress). Widely used in petrochemical, nuclear power, and advanced energy industries, it is the benchmark material for high-temperature components where conventional Incoloy 800 or low-alloy steels fail to meet creep performance requirements.

International Grade Comparison

Physical Properties (Room Temperature, Key Brief Indicators)

Chemical Composition (Mass Fraction, Key Elements)

5. Product Characteristics

1.Superior High-Temperature Creep & Rupture Strength: Optimized carbon content and uniform grain size (ASTM 5-8 grades) ensure stable performance under long-term stress at 980°C, meeting strict creep life requirements (e.g., 100,000 hours at 850°C);

2.Exceptional High-Temperature Corrosion Resistance: Chromium-nickel-titanium synergy forms a dense, stable oxide film, resisting oxidation, scaling, and carburization in high-temperature atmospheres (e.g., furnace flue gas, superheated steam);

3.Excellent Thermal Fatigue Resistance: Low thermal expansion coefficient and balanced matrix structure minimize deformation or cracking caused by frequent high-temperature cycling (critical for furnace tubes and heat exchangers);

4.Processability Tailored for High-Temp Service: Compatible with hot forging, rolling, and welding; post-weld stabilization heat treatment (e.g., 980-1040°C annealing) optimizes grain structure and creep performance.

Metallographic Structure

At room temperature, it features a face-centered cubic crystal structure (austenitic matrix) with uniform grain size (ASTM 5-8 grades). Controlled carbon content promotes fine, dispersed MC-type carbides (mainly TiC) at grain boundaries and within grains—these carbides act as "strengthening pins" to inhibit grain sliding under high temperatures, significantly enhancing creep resistance without inducing brittleness.

Product Forms and Executive Standards