Scc is often associated with chlorides, but can also occur with caustics and other corrosive media. Inconel 600uns no6600 a nickelchromium alloy with good oxidation resistance at high temperatures and resistance to chlorideion stresscorrosion cracking, corrosion by highpurity water, and caustic corrosion. Alloy 400 is a nickelcopper solid solution strengthened alloy. Application of the alloy is useful in the chemical, pulp and paper, aerospace and heat treating industries to name a few. In addition to its corrosion resistance, alloy 690 has high strength, good metallurgical stability, and favorable fabrication characteristics.
As a solution strengthened material, monel alloy 400 displays good strength, toughness and corrosion resistance at temperatures up to 400c. Nace mr0175 once allowed the use of inconel 600 in its 1997 revision, however, it precludes it in the following revisions. This nickel alloy was designed for service temperatures from cryogenic to elevated temperatures in the range of 2000 f. Stress corrosion cracking scc of nickelbased alloys. A bent nicu monel 400 alloy tube, which operated as part of a pipeline in a petrochemical distillery installation, failed by throughthickness cracking. Alloy 600 is a nickelchromiumiron, solid solution strengthened alloy used for applications that require corrosion and high temperature resistance. Inconel alloy 600 uns number n06600 other common names. Highperformance nickel alloys for sour oil and gas fields. The survey of alloy 600 cracking suggests that alloy 600 and its associated welds alloys 182 and 82 are susceptible to crack nucleation and growth in a wide range of applications. The alloy excels applications requiring service in waters, including sea and brackish water. Controlled chemical composition limits are applied in the nuclear industry to eliminate the risk of stress corrosion cracking by high purity water containing chloride ions. The most serious cracking problem with nickel alloys is hot cracking in either the weld metal or close to the fusion line in the haz with the latter being the more frequent.
Le calvar, some possible mechanisms of intergranular stress corrosion cracking of alloy 600 in pwr primary water, in proc. Alloy 600 and alloy 690 were both susceptible to cracking in the simulated resin intrusion environment. Stresscorrosion cracking of a monel 400 tube springerlink. Heat exchangers in commercial nuclear systems have shown scc in only a fraction of a percent of the tubes in high temperature water, but laboratory scc of nicontaining alloys have been demonstrated by several research groups. Monel 400 has low corrosion rate in flowing seawater, therefore it is widely used in marine applications. Plant experience with alloy 600 cracking and boric.
These alloys are wellknown for their excellent corrosion resistance to seawater. Stress corrosion cracking the strength of an alloy is a governing factor in its resistance to environmental cracking. Alloy 600 is employed in the fabrication of steam generator tubes in the nuclear power plants. Alloy 625 has excellent fatigue strength and stress corrosion cracking resistance to chloride ions.
Alloy 400 is exceptionally resistant to chloride stress corrosion cracking. The alloy has superb corrosion resistance to caustic environments. Alloy 600 is resistant to corrosion by many organic and inorganic compounds and also makes it virtually immune to chlorideion stresscorrosion cracking. Intergranular stress corrosion cracking scc of inconel 600 is of concern to the nuclear power industry. Furthermore, the chromium material in alloy 600 provides resistance to sulfur substances. Stress corrosion cracking behavior of nickel base alloys.
Monel vs inconel stainless shapes nickel alloy distributor. The main source of this problem is sulphur but phosphorus, lead, bismuth and boron also contribute. Correlation between grain boundary migration and stress. Used for furnace components, in chemical and food processing, in nuclear engineering, and for sparking electrodes. Inconel 600 buy inconel 600 sheet, inconel 600 plate. This is achieved through the addition of titanium and aluminum which is. Alloy 600 is used extensively in the chemical industry for its strength and corrosion resistance.
The alloy is characterized by moderate strength, good weldability, good general corrosion resistance and toughness. Well, dry chlorine cl 2 is not corrosive to steels at ambient temperatures and is commonly shipped and handled in carbon steel equipment, with higheralloy materials such as monel 400 and hastelloy c276 used for critical parts. Alloy 600 uns n06600 description alloy 600 is a nickelchromiumiron, solid solution strengthened alloy used for applications that require corrosion and elevated temperature resistance. Similarly, the chromium content of alloy 600 is an improvement over alloy 200 commercially pure nickel. Monel alloy k500 has been found to be resistant to a sourgas environment. Alloy 600 is one alloy used in solutions of magnesium chloride.
Alloy 600 inconel 600 is a nickelchromium alloy used for applications that require corrosion and high temperature resistance. Monel alloy 400 2 table 3 thermal properties of monel alloy 400 the nominal roomtemperature tensile properties of monel alloy 400 are shown in table 4. Alloy 600 can be both hot formed and cold formed using typical processes. Analyses with alloy 600 have shown that it is partially more resistant than monel 400 or nickel to attack caused by hypochlorites particularly where available chlorine magnitude is above 3gl. It is resistant to brine and immune to stress corrosion cracking and pitting in chloride and caustic alkaline. Nickelcopper alloys an overview sciencedirect topics. The high chromium content of alloy 600 raises its oxidation resistance, whilst the high nickel content provides good corrosion resistance under reducing conditions. The tower provided a caustic solution naoh to remove hcl from the stream, before the latter was directed to a burner. Industries and applications the unique properties of alloy 600 make it.
Figures 2 and 3 are based on typical data that show relationships between properties of rods and forgings and. Incoloy 625, alloy 400, inconel 400, alloy 600, c276, 200, 800, 800h, 1. Performance of nickel and high nickel alloys in chloride media. Stress corrosion cracking scc is a common issue with many specialty alloys. Welding alloy 600 can be achieved via shielded metalarc welding, tig, and mig. Inconel alloy 600 also demonstrates resistance to dry chlorine up to 538c. A nickelchromium alloy with good oxidation resistance at high temperatures and resistance to chlorideion stresscorrosion cracking, corrosion by highpurity water, and caustic corrosion. Corrosion resistant alloys nitronic hastelloy inconel and. Monel 400 is characterized by good general corrosion resistance, good weldability and moderate to high strength. The main factor that influences corrosion rates of steels by. Inconel 600 is highly resistant to chlorideion stresscorrosion cracking due to the high nickel content.
It is one of the biggest groups in the family of nickel alloys that include alloy 600, alloy 825, alloy 800 and hastelloy g30. All the alloys are best welded in the annealed or solution treated condition and this applies particularly to the precipitation hardenable alloys such as inconel 718. The alloy also has excellent mechanical properties and presents the desirable combination of high strength and good workability. Advantages of seamless nickel pipes nickel alloy tubes have excellent corrosion resistance in. The alloy also displays very good levels of resistance to chloride stresscorrosion cracking, ammonia, pitting in fresh and salt water, exhaust gasses and most organic acids and. Monel 400 is a nickelcopper alloy that is hardened by cold working only. In strong oxidizing solutions, like hot, concentrated nitric acid, alloy 600 has poor resistance. Pdf stress corrosion cracking scc of nickelbased alloys. Monel 400 is a nickelcopper alloy, resistant to sea water and steam at high temperatures as well as to salt and caustic solutions.
Monel alloy 400 na, n04400 is a nickelcopper alloy resistant to seawater and steam at high temperatures and widely used in the chemical, oil and marine industries. Inconel 600 is a nickelchromium alloy with good oxidation resistance at high temperatures and resistance to chlorideion stresscorrosion cracking, corrosion by highpurity water, and caustic corrosion. Nickel alloy 500 and monel k500, commonly known as uns n05500, is a nickelcopper based alloy which combines the excellent corrosion resistance of nickel alloy 400 with added advantages such as greater strength and hardness, making it superior to the other nickelcopper based alloys. Primary water stress corrosion cracking pwscc of ni base alloys, such as alloy 600, is one of the main issues associated with longterm operation of nuclear power plants. Service temperatures for inconel 600 can be from cryogenic to 2000f. Inconel 600 is a nickelchromiumiron alloy with good corrosion resistance, oxidation resistance, and high strength at high temperatures. Monel 400 is a nickelcopper alloy with excellent corrosion resistance in a wide variety of media. The mechanism of stress corrosion cracking of alloy 600 in. The intent of inspection is to identify and remediate the cracking before it can challenge safety systems. They have been used as propellers, pump shafts, impellers and condenser tube materials.
This alloy also has good workability, weldability and high strength. Alloy 400 is attacked in sulfurbearing gases above 700 f 371 c and molten sulfur attacks the alloy at temperatures over 500 f 260 c. Inconel 600 uns n06600 is endorsed by nace mr0103 but no longer endorsed by mr0175. Further precautions to be taken with the commoner welding processes and recommendations on the welding of specific alloys will be covered in part 2. Scott and le calvar proposed for the first time that pwscc in alloy 600 was associated with internal oxidation phenomena selectively occurring at grain boundaries. Advantages of seamless nickel pipes nickel alloy tubes have excellent corrosion resistance in both low and high temperature applications. The minerals, metals and materials society, warrendale, pa 1993 p. Alloy 600 is a nonmagnetic nickelchromiumiron high temperature alloy with an excellent combination of high strength, hot and cold workability and high corrosion resistance. Additionally, while we wrote about how monel is better when dealing with sea water and corrosion resistance, it is worth noting that inconel 625 specifically does particularly well at resisting sea water and marine conditions, in the chance you are looking for a happy medium. Inconel 600 is a nickelchromium alloy used for applications that require corrosion and high temperature resistance. Monel 400 is a nickelcopper alloy about 67% ni 23% cu that is resistant to sea water and steam at high temperatures as well as to salt and caustic solutions. Dec 31, 2019 the survey of alloy 600 cracking suggests that alloy 600 and its associated welds alloys 182 and 82 are susceptible to crack nucleation and growth in a wide range of applications. Review of the stress corrosion cracking of inconel 600. The high chromium content of alloy 600 raises its oxidation resistance, whilst the high nickel.
Monel 400, nickel and inconel 600 are resistant to the dilute hypochlorite solutions, often comprising of less than 500 ppm, introducing chlorine. Highperformance alloys for resistance to aqueous corrosion. Corrosion resistant alloys nitronic hastelloy inconel and monel. With high nickel content, inconel alloy 600 is virtually immune to chlorideinduced stress corrosion cracking. Seamess nickel alloy tubes pipe incoloy 625, alloy 400.
Monel 400 corrosion characteristics in hydrofluoric acid hf. Corrosion of common alloys in dry chlorine cl2 penflex. This nickel alloy was designed for service temperatures from cryogenic to elevated temperatures in. The monel nicu alloys highperformance alloys for resistance to aqueous corrosion. The pipeline was used to carry a stream of gaseous hydrocarbons containing hydrochloric acid hcl into a reaction tower. Stress corrosion cracking the strength of an alloy is a governing factor. Alloy 400 is a solid solution alloy that can only be hardened by cold working. Monel 400 also has excellent resistance to stress corrosion cracking in most freshwaters. It is a broadly studied material for its immunity in stress corrosion cracking in. Inconel 600 is combination of nickel chromium and iron provides a standard material for the chemical industry and the automotive engine, aeroengine and airframe sectors. Controlled sulfur added for improved machinability over alloy 400. The corrosion resistance of monel alloy k500 is substantially equivalent to that of alloy 400 except that, when in the agehardened condition, alloy k500 has a greater tendency toward stresscorrosion cracking in some environments.
Inconel 600 strip alloy offers outstanding resistance to organic as well as inorganic substances, chloride ion stress corrosion cracking, and also oxidizing conditions and reducing. Service temperatures for alloy 600 can be from cryogenic to 2000f. Inconel 600 welding rod inconel 600 magellan metals. The most common type of stress corrosion cracking in stainless steels occurs in chloride environments, which will be the focus of. Alloy 690, however, exhibited the greatest resistance to scc of the two alloys. It is a broadly studied material for its immunity in stress corrosion cracking in warm water and caustic media. In this case the heat treated inconel 725hs specimens surpassed this test limit and there was no cracking in the sour brine environment, while cold worked inconel 625 exhibited cracking after 10 days.
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