China Uns N08028 Alloy 28 Sanicro 28 Corrosion Resistance Nickel Alloy Tube, Find details about China N08028, Alloy28 from Uns N08028 Alloy 28 Sanicro 28 Corrosion Resistance Nickel Alloy Tube
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Due to its outstanding corrosion properties, Sanicro® 28 can be used in the most diverse environments. Listed below are a few examples of applications for which this alloy is particularly suitable.
Today, Sanicro® 28 is the most widely used metallic material for evaporator tubes in the manufacture of phosphoric acid by the "wet " method. Several units have now been in service for more than 10 years. The graphite heat exchangers, replaced by Sanicro® 28, often had repeated problems with broken tubes and loss of production.
Sanicro® 28 is a suitable material for piping and heat exchangers, particularly at concentrations of between 40 and 70% of deaerated acid and over 85%. Sanicro® 28 has approximately the same resistance as Alloy C in concentrated acid (98% H2SO4).
Sanicro® 28 is used for production tubing, casing and liners in deep, sour gas wells. The material is also recommended for oil wells with a corrosive environment. For these purposes, tubes are supplied cold rolled with high strength. In the solution annealed condition, Sanicro® 28 is also used as piping for transporting of corrosive oil and gas and for heat exchangers in treatment facilities. Sanicro® 28 wirelines are used for lowering tools and controlling instruments in deep oil and gas wells.
Fluoride-bearing off-gases can form during the manufacture of phosphoric acid and mixed fertilizers. These off-gases must be disposed of for environmental reasons. Sanicro® 28 is ideal for this purpose. Tests have shown it to be preferable to higher alloyed CrNiMo grades for the recovery of fluoride-bearing gypsum.
Due to its high resistance to SCC, pitting and crevice corrosion, Sanicro® 28 has been selected for heat exchangers in nuclear power plants.
Its high resistance to pitting and crevice corrosion makes Sanicro® 28 a very suitable material for seawater-carrying piping and seawater-cooled heat exchangers. This is confirmed by practical experience.
Sanicro® 28 has replaced nickel alloys, CuNi, bimetallic tubes and coated carbon steel tubes, which failed due to corrosion. The performance of Sanicro® 28 has been excellent.
In seawater-cooled heat exchangers and heat exchangers that work with chloride-bearing cooling water, Sanicro® 28 offers high corrosion resistance to both the water and the cooled medium.
When a seawater-cooled plant is shut down, there is no need to drain the piping system or flush with fresh water, provided that the shutdown period is shorter than one month and the water temperature is lower than 30°C (85°F).
The duplex stainless steel Sandvik SAF 2507® is more resistant than Sanicro® 28 in sea water.
C | Cr. | Ni | Fe | Mn | Si | Mo | Cu | P | S |
0.03 | 26 to 28 | 30 to 32.5 | Bal. | 2.5 | 1 | 3 to 4 | 0.6 to 1.4 | 0.03 | 0.03 |
Material and Grade | Delivery Condition | Yield Strength (Mpa) Rp0.2 | Tensile Strength (Mpa) Rm | Elongation e (%) | Mean Hardness number (HRC) | |
ALLOY 28 (UNS8028) | CH | Min | Max | Min | Min | Max |
758 | 965 | 793 | 12 | 33 |
Sanicro® 28 was originally developed for use in the manufacture of phosphoric acid, especially for heat exchangers in the concentration unit, where corrosive conditions are at their worst.
Phosphoric acid, manufactured by the "wet" method, contains varying concentrations of impurities derived from the raw material, the phosphate rock. The most dangerous of these impurities are chlorides, Cl - , and fluorides in free form, F - . Laboratory tests carried out in wet process phosphoric acid have shown that Sanicro® 28 is far more resistant to impurities of this kind than other high alloy materials. Figure 1 shows the corrosion rate in contaminated phosphoric acid at different chloride concentrations.
Temperature is another factor that has a great influence on corrosion. See figure 2.
Laboratory tests at 200°C (390°F) in contaminated 95% super phosphoric acid gave the following corrosion rates after 20 days: Sanicro® 28, 0.03 mm/year (1.2 mpy); Alloy 904L, 0.10 mm/year (4.0 mpy); UNS N08020, 0.23 mm/year (9.2 mpy); Alloy G, 0.03 mm/year (1.2 mpy).
Table 1 Chemical compositions of materials tested
Material | Chemical | Composition | Nominal, % | |||||
C | Cr | Ni | Mo | Cu | W | Co | Others | |
Sanicro 28 | 0.02 | 27 | 31 | 3.5 | 1.0 | - | - | - |
Alloy 904L | 0.02 | 20 | 25 | 4.5 | 1.5 | - | - | - |
UNS N08020 | 0.07 | 20 | 34 | 2.5 | 3.3 | - | - | Nb |
Alloy 825 | 0.05 | 21.5 | 42 | 3 | 2.3 | - | - | Ti |
Alloy G | 0.03 | 22 | 45 | 6.5 | 2 | 1.0 | 2.5 | Nb |
Alloy C | 0.08 | 15.5 | 54 | 16 | - | 4 | 2.5 | - |
- | - |
seamless pipe | Round pipe | Out diameter: | 1/8"-24"(6mm-630mm). |
Wall thickness: | ANSI 5S-160S (0.9mm-100mm) | ||
Square pipe | 20x20x-200x200:thickness2-50mm | ||
rectangular pipe | 10x20-150x100,thickness:2-50mm | ||
Hex pipe | Out hex or Round Inside bore or hex | Flat to flat 16-70mm, thickness:3-10mm With drawing | |
Oval tube | With drawing | ||
Welded type | Round pipe | Out diameter: | OD6-2500MM |
Wall thickness: | Thickness:1-50mm | ||
Square pipe | 10x10-200x200,thickness1-3mm | ||
Rectangular pipe | 10x20-150x100,thickness:1-3mm | ||
Oval tube | As drawings | ||
Manufacture Standard: | ASTMA213/312/269/511/789/790, GOST9940/9941,DIN17456/17458/EN10206/17440 JIS3459/3463,GB13296/14976/9948/5310/8142/8143 | ||
stainless steel | TP304,304L,304H,304N,316,316L,316Ti,317L,310S,321,321H,347H,S31803, S32750,347,330,825,904L, 12X18H9,08X18H10,03X18H11,08X18H10T,20X25H20C2,08X17H13M2T,08X18H12E 1.4301, 1.4306, 1.4401, 1.4404, 1.4435, 1.4541, 1.4571, 1.4563, 1.4462, 1.4845, SUS304, SUS304L, SUS316, SUS316L, SUS321, SUS310S etc. | ||
Nickel alloy | Hastelloy: UNS N10001, N10665, N10675, N06455, N06022, N10276, N06200, N06035, N06030, N06635, N10003, N06002, R30188, N06230, R30556 Inconel: UNS N06600, N06601, N06617, N06625, N07718, N07750, N08800, N08810, N08811, N08825, N09925, N08926 Monel: UNS N04400, N05500 Precipitation-hardening Steels: 254SMO/S31254, 17-4PH, 17-7PH, 15-7PH Nickel: N4/UNS N02201, N6/UNS N02200 | ||
Titanium and titanium alloy | GR1,GR2,GR5,GR7,GR9,GR12 | ||
Process methods: | cold drawn, cold rolling,welded | ||
Surface & Delivery condition: | Solution annealed and pickled, grey white (polished),with plain ends/bevel edges ends,Hairline | ||
Length: | Max25 meters | ||
Packing: | in seaworthy wooden cases or in bundles | ||
Min order quantity: | 0.5 ton each size for common steel. | ||
Delivery date: | TP304,TP310S,TP316L pipes usually have stock,others Min. 10 days | ||
Certificates: | ISO9001:2000 quality system and Mill test Certificate supplied |