Product introduction

Inconel alloy plate refers to a sheet product made from this alloy through a specific processing technique. Its excellent heat resistance, corrosion resistance, and high strength make it widely used in extreme working conditions in aerospace, energy, chemical, and other industries.

Core features

1. High-Temperature Resistance

The nickel content typically ranges from 50% to 70%. Ni's face-centered cubic structure maintains a stable crystal structure at high temperatures, resisting softening. Furthermore, the addition of elements such as Cr (10%-25%), Mo, and W creates strengthening phases (such as γ' phase and carbides), ensuring the sheet maintains sufficient strength and creep resistance (i.e., resists deformation under long-term high-temperature stress) even at temperatures of 600-1200°C.

For example, Inconel sheet is often used in the combustion chambers and outer rings of turbine blades in aircraft engines to withstand high-temperature erosion from combustion gases.

2. Corrosion Resistance

Cr forms a dense Cr₂O₃ passivation film on the plate surface, preventing further attack from corrosive media such as oxygen, acids, and alkalis. Elements such as Cu (for sulfuric acid resistance) and Ti (for stress corrosion cracking resistance) are also added to address specific corrosive environments.

For example, reactors and heat exchangers in the chemical industry are resistant to corrosion from strong acids, alkalis, and seawater.

3.Low temperature resistance: 

Some Inconel alloys (such as Inconel 718) can maintain excellent toughness even at ultra-low temperatures (such as liquid oxygen and liquid nitrogen environments, -269°C), eliminating the risk of "cold brittleness". They are often used to manufacture cryogenic fuel tanks for space rockets.

4. High Strength and Toughness

Through alloying (such as the addition of Al and Ti to form a γ' phase) and subsequent heat treatment, the plate combines high strength with excellent impact toughness, allowing it to withstand complex mechanical loads (such as high pressure and vibration).

Grade

Production process

The production of Inconel alloy plates has extremely high requirements for tissue purity and uniformity. Its core process can be divided into four steps: smelting → plastic processing → heat treatment → finishing:

1. Smelting: Ensuring purity and uniformity of components

Using a dual/triple process of vacuum induction melting (VIM) + vacuum arc remelting (VAR) or VIM + electroslag remelting (ESR)

2.Plastic Processing: Rolling to Shape and Refine the Microstructure

The ingot undergoes multiple rolling steps to transform the coarse as-cast structure into a fine deformed structure while also controlling the thickness and size of the plate.

Heating - hot rolling - cold rolling - intermediate annealing

3.Heat Treatment: Optimizing Performance (Key Step)

Targeted heat treatment processes are employed based on the performance requirements of different grades. The core goal is to adjust the alloy's internal structure by controlling temperature and cooling rate.

Example 1 (Inconel 718): Solution treatment (holding temperature at 1065°C, followed by water cooling) plus aging treatment (holding temperatures at 720°C and 620°C) uniformly precipitates the γ' phase (Ni₃Al/Ti), significantly improving strength.

Example 2 (Inconel 600): Annealing (holding temperature at 1010-1120°C, followed by air cooling) is typically used to achieve a stable austenitic structure, thereby optimizing corrosion resistance and toughness.

4. Finishing and inspection: ensure dimensional accuracy and quality

Application areas

In the aerospace field, it is used to manufacture aircraft engine components, rocket thrusters and other structural parts in high-temperature environments; in the chemical industry, it is suitable for containers, pipes, valves and other components for various corrosive media; in the nuclear industry, it can be used for control rods, fuel rods and other nuclear components in nuclear reactors; in the oil and gas industry, it can be used for oil well drill pipes, valves and pipelines, etc., to withstand high-temperature and high-pressure oil and gas environments.