Inconel 690/UNS N06690/W.Nr.2.4642 Sheet Bar Tube/Pipe Loop

Overview

Inconel 690 is a superalloy composed mainly of nickel and chromium, but also contains small amounts of iron, copper, manganese and other elements. It has good high-temperature corrosion resistance, oxidation resistance, cold and hot processing performance and low temperature mechanical properties, can still maintain high strength at 650℃ high temperature. In addition, Inconel 690 alloy has a high corrosion resistance to various waste gases, alkaline solutions and most organic acids and compounds, especially not prone to chloride ion corrosion cracks. However, it should be noted that under high concentrations of caustic alkali or high temperature mercury conditions, the alloy may develop stress corrosion cracks.

A notable characteristic of Inconel 690 alloy is its excellent resistance to intergranular corrosion and intergranular stress corrosion cracking, which makes it particularly suitable as a material for steam generator heat transfer tubes in pressurized water reactor nuclear power plants. In practical applications, no damage has been reported in the use of Inconel 690 alloy.

Limiting Chemical Composition, %

Nickel.....................................................................................................................................................................................58.00 min. 

Chromium...........................................................................................................................................................................27.00-31.00

Iron........................................................................................................................................................................................7.00-11.00

Carbon....................................................................................................................................................................................0.05 max.

Manganese.............................................................................................................................................................................0.50 max.

Silicon.....................................................................................................................................................................................0.50 max.

Sulfur.....................................................................................................................................................................................0.015 max.

Phosphorus.............................................................................................................................................................................0.02 max.

Copper.....................................................................................................................................................................................0.50 max.

Physical Constants

Mechanical properties

Corrosion Resistance

Inconel 690 is a special corrosion resistant superalloy with excellent corrosion resistance. This is mainly due to its high content of nickel and chromium elements, as well as special alloying treatment.

In extreme environments such as high temperature, high pressure, strong acid and alkali, Inconel 690 can still maintain good corrosion resistance and can effectively resist the erosion of corrosive gases and liquids. At the same time, the alloy can form a dense oxide film in high temperature oxidation environment, which further improves its corrosion resistance. In addition, Inconel 690 has good resistance to chloride and high temperature and pressure water stress corrosion, as well as resistance to strong oxidizing media and mixed corrosion. Inconel 690 is a special corrosion resistant superalloy with excellent corrosion resistance. This is mainly due to its high content of nickel and chromium elements, as well as special alloying treatment.

In extreme environments such as high temperature, high pressure, strong acid and alkali, Inconel 690 can still maintain good corrosion resistance and can effectively resist the erosion of corrosive gases and liquids. At the same time, the alloy can form a dense oxide film in high temperature oxidation environment, which further improves its corrosion resistance. In addition, Inconel 690 has good resistance to chloride and high temperature and pressure water stress corrosion, as well as resistance to strong oxidizing media and mixed corrosion.

Heat treatment

The heat treatment of Inconel 690 is an important process, which mainly includes two states: solution treatment and aging treatment.

Solution treatment is an important part of the Inconel 690 heat treatment process. In this process, the alloy is heated to high temperatures and held for a period of time to allow its internal organization to fully diffuse and homogenize. Solution treatment can eliminate the internal microstructure defects and improve the mechanical properties of materials. At the same time, this process also softens the alloy, making it easy to carry out subsequent machining and forming operations.

Aging treatment is another important part of the Inconel 690 heat treatment. After solution treatment, the alloy is rapidly cooled to room temperature and held for a period of time to promote aging strengthening of the internal structure of the alloy. This process can adjust the strength, toughness and corrosion resistance of the material by controlling the aging time and temperature. After aging treatment, the mechanical properties of Inconel 690 can be significantly improved to meet the requirements of a variety of high temperature, high pressure and corrosive environments.

In addition, the heat treatment of the Inconel 690 includes special heat treatment (TT treatment). This treatment is a heat treatment process after solid solution treatment at a constant temperature for a period of time, mainly improve the distribution of carbide on the grain boundary, so that the Cr element in the matrix diffusion to the grain boundary, to reduce the Cr poverty phenomenon at the grain boundary, so as to improve the Inconel 690 intergranular corrosion resistance.

Avaliable Forms

We provide you with a variety of product forms, including but not limited to

● Bar & Rod

● Pipe & Tube

● Coil & Strip

● Plate & Sheet 

● Wire & Welding

● Fitting (Flange,Botls,Elbow, Tee...)

● Customize