Inconel vs Hastelloy: Corrosion Resistance & High-Temp Applications

In high-temperature and corrosive environments, both Inconel and Hastelloy exhibit unparalleled advantages, making them essential choices across various industrial sectors. As critical nickel-based alloy tubes and high-temperature materials, these two alloys play a core role as corrosion-resistant tubing in industries such as oil and gas, chemical processing, aerospace, and nuclear power. This article aims to provide an in-depth comparison of Inconel and Hastelloy, helping procurement engineers evaluate and select the most suitable alloy based on high-temperature resistance, corrosion resistance, and overall engineering applicability.

Next, we will take a closer look at the fundamental composition of these two alloys—particularly their chemical composition and strengthening mechanisms. A detailed comparison of these aspects will not only help us understand their respective advantages but also provide a more scientific basis for material selection in engineering applications.

Inconel alloys are primarily nickel-chromium alloys.

Hastelloy alloys are primarily nickel-molybdenum-chromium alloys.

Key Differences Between Inconel and Hastelloy

1. Composition Ratio:

Inconel alloys have a higher chromium content, which enhances their oxidation resistance at high temperatures.

Hastelloy alloys contain a higher molybdenum content, making them more corrosion-resistant, particularly in environments containing hydrochloric acid.

2. Role of Strengthening Elements:

Inconel alloys: Aluminum and titanium contribute to improved high-temperature strength and oxidation resistance.

Hastelloy alloys: Molybdenum, chromium, and tungsten primarily enhance corrosion resistance.

3. Properties:

Inconel alloys: These are typical high-temperature alloys, specifically designed for extreme heat (up to 1200°C) and oxidation-prone environments.

Hastelloy alloys: These are corrosion-resistant alloys that can also withstand high temperatures to some extent but are mainly designed for superior corrosion resistance, particularly in low-to-moderate temperature corrosive environments.

Performance Differences Due to Composition

High-Temperature Suitability:

Inconel alloys: With high chromium content (>20%) and Al/Ti strengthening, they exhibit excellent oxidation resistance in environments ranging from 800-1000°C.

Hastelloy alloys: Due to lower chromium content, they are more prone to oxidation instability at prolonged high temperatures. However, they remain stable in a wide temperature range, from cryogenic (-196°C) to moderate high temperatures (below 600°C).

Corrosion Resistance in Different Media:

Inconel alloys: Perform better in oxidizing acids such as nitric acid and phosphoric acid.

Hastelloy alloys: With high Mo (15-17%) and W (3-4.5%), they offer exceptional resistance in hydrochloric acid, sulfuric acid, and chloride-containing solutions, with a corrosion rate 1-2 orders of magnitude lower than Inconel in these environments.

Processing Characteristics Comparison

Inconel alloys: Prone to work hardening during machining, with a narrow hot-working temperature range.

Hastelloy alloys: Due to high Mo content, the work-hardening rate exceeds 80%, requiring intermediate annealing (recommended annealing temperature: 1150°C).

Welding Performance Comparison

Inconel alloys: Moderate welding difficulty, though some grades (e.g., Inconel 718) are sensitive to hot cracking.

Hastelloy alloys: Generally easier to weld, with lower susceptibility to cracking.

Core Competitive Characteristics Comparison

Application Environments and Industry Guide

Applicable Temperature:

Inconel alloy: >600℃

Hastelloy alloy: <300℃

Global Supply Expertise: Precision-Crafted Inconel & Hastelloy Tubes for Critical Industries

We supply Inconel and Hastelloy nickel alloy tubes in the following grades. Sizes can be customized according to customer specifications, and third-party inspection is accepted.

Inconel: 600/601/625/718

Hastelloy: C-276/C-22/C-2000/B-3/B-2

Inconel vs Hastelloy Tube