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YST Alloy (Corrosion and wear resistant special stainless steel casting)
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YOKOTA's special stainless steel casting, YST series, with enhanced pitting
and crevice corrosion resistance as well as wear resistance, has been favorably
received as a standardized material suitable for pumps and valves in equipment
for anti-pollution treatment, seawater treatment, and chemical processing
among others.
In particular, this YST Alloy has been adopted as the pump material for
wet-type smoke discharging desulfurizers under a variety of severely corrosive
and abrasive conditions, proving its excellent durability and reliability
even under severe conditions.
Moreover, YOKOTA's duplex stainless steel YST130N, not only shows outstanding seawater resistance, but also is applicable
to many different types of liquid as an excellent corrosion and wear resistant
material.
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Characteristics of YST Alloy
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Compared with JIS materials such as SCS13, SCS14, and Carpenter 20 (SCS23),
a widely used corrosion resistant material, YST Alloy has the following
advantages:
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Excellent corrosion resistance, and especially effective against local
corrosion due to chloric ion conditions.
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Improved wear resistance due to improved hardness, resulting in both corrosion
resistance and wear resistance.
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Excellent resistance to pitting and crevice corrosion in seawater.
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Easily welded by covered arc or TIG welding without preheating or residual
heating.
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Applications of YST Alloy
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Wet-type flue gas desulfurizer drainage treatment system
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Acid-containing drainage treatment system for semiconductor plant
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Incinerator drainage treatment system
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Boiler/Scrubber circulating system
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Seawater desalination system
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Pulp and paper process water
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Electroplating wastewater
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Wear resistant high Cr steel casting
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Developed for sand pump material, wear resistant high Cr steel casting
(CCR10) is used in pumps for construction work, sedimentation ponds, and
also used in pumps to treat lime-gypsum liquid and other high density,
slurry liquid.
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Metallographic
structure |
Material
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Characteristic, Use
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Handling liquid (Our supply record)
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Austenite
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YST30
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Austenite stainless steel with improved corrosion resistance and wear resistance
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Gypsum slurry
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YST40
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Austenite high alloy stainless steel with improved corrosion resistance
such as acid resistance and alkali resistance
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Sulfuric acid / hydrochloric acid wastewaters
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Duplex
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YST130A
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Duplex stainless steel having high corrosion resistance and wear resistance.
Mainly used for pump casings
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Gypsum slurry, Lime slurry, Sludge, Coal sludge, Wastewater containing
iron powder slurry, Zinc slurry, Sulfuric acid slurry, SiO2 slurry.
Dilute sulfuric acid + magnesium hydroxide + gypsum, Copper electrolyte
+ washing water + dust, Titanium sulfate solution
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YST130C
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Duplex stainless steel with improved wear resistance than YST130A.
Mainly used for pump impellers
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Gypsum slurry, Lime slurry, Zinc slurry, SiO2 slurry, Sulfuric acid slurry
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YST130N
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High corrosion resistant and particularly seawater resistant stainless
steel.
Duplex stainless steel well-balanced between pitting corrosion resistance,
crevice corrosion resistance, wear resistance, and seawater resistance.
Especially high corrosion resistance under chlorine ion environment.
Used for pump and valve components
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Seawater, Salt water, Hot spring water, Drainage (acid, alkali, hydrofluoric
acid, etc.)
Hydrochloric acid, Sulfuric acid.
Gypsum slurry, Lime slurry, Highly corrosive slurry liquid, Salt slurry.
Coal tar, Polishing process wastewater, Titanium sulfate solution, Concentrated
brine
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High chromium
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CCR10
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High chromium steel casting with superior wear resistance.
Used for pump components
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Water containing neutral scales, Gypsum slurry, Lime slurry, Magnesium
hydroxide slurry
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Note: YST30 can be replaced by YST130N.
(For reference) We also manufacture the following JIS materials.
Metallographic
structure |
Material
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Characteristic, Use
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Handling liquid (Our supply record)
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Austenite
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SCS13
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General corrosion resistance
(SUS304 equivalent)
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Industrial water, Pure water, Drainage (acid, alkali), Miscellaneous wastewater, Pulp, Caustic soda
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SCS14
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Improved corrosion resistance and pitting corrosion resistance than SUS
304
(SUS316 equivalent)
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Seawater, Pulp raw material, Chlorine-mixed water, Activated sludge filtrate,
Factory wastewater, Acidic wastewater, Concentrated sulfuric acid
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SCS16
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Improved grain boundary corrosion resistance than SUS 316
(SUS316L equivalent)
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Ammonia, Wastewater containing surfactant, Hot water containing salt, Sulfuric
acid solution
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| SCS19 |
Improved grain boundary corrosion resistance than SUS 304. Reduced heat
effect by welding
(SUS304L equivalent) |
Nitric acid, Nitric acid aqueous solution + slurry |
| SCS23 |
High alloy stainless steel with corrosion resistance to acid and alkali |
Zinc electrolyte, Sulfuric acid, Organic wastewater, Wastewater containing
heavy metal, Sodium hydroxide slurry |
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Duplex
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SCS10
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Improved pitting corrosion resistance and crevice corrosion resistance
than SUS 329J1
(SUS329J3L equivalent)
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Wastewater containing slurry, Flue gas treatment tower circulating water,
Salt water, NaCl / Na2SO4 slurry
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SCS11
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Acid resistance, pitting corrosion resistance and high strength
(SUS329J1 equivalent)
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Brine
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Corrosion resistance, Wear resistance
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Fig.1 All-surface corrosion resistance
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Fig.2 Pitting corrosion resistance
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As Fig.1 and 2 show, YST Alloy has excellent local corrosion resistance
especially to liquids containing chloric ion, in addition to all-surface
corrosion resistance. Fig.3 shows that YST Alloy also has excellent wear
resistance, thus being suitable for various kinds of liquid.
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Fig.3 Corrosion resistance and wear resistance
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Fig.4 Wear resistance (Rate of wear, counting the wear of SCS14 by 20%
slurry as 100)
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Fig.5 Corrosion resistance and wear resistance (Rate of wear, counting
the wear of SUS316 by 5% slurry as 100)
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YST130N is more suitable than YST130A for highly corrosive slurry liquid.
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