Special Stainless Steel (Corrosion and wear resistant)

Special Stainless Steel
YST series

Corrosion and wear resistant special alloy for various kinds of liquid

YST Alloy (Corrosion and wear resistant special stainless steel casting)

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.

Characteristics of YST Alloy

Compared with JIS materials such as SCS13, SCS14, and Carpenter 20 (SCS23), a widely used corrosion resistant material, YST Alloy has the following advantages:

Excellent corrosion resistance, and especially effective against local corrosion due to chloric ion conditions.

Improved wear resistance due to improved hardness, resulting in both corrosion resistance and wear resistance.

Excellent resistance to pitting and crevice corrosion in seawater.

Easily welded by covered arc or TIG welding without preheating or residual heating.

Applications of YST Alloy

Wet-type flue gas desulfurizer (

>"Current Topics: Slurry Self-Priming" )

Wet-type flue gas desulfurizer drainage treatment system

Acid-containing drainage treatment system for semiconductor plant

Incinerator drainage treatment system

Sewage treatment system (

>"Current Topics: Sewage Treatment" )

Refinery wastewater treatment system (

>"Current Topics: Steel Works" )

Boiler/Scrubber circulating system

Seawater desalination system

Seawater pump (

>"Current Topics: Seawater Intake", "Aquarium", "Undersea Tunnel")

Pulp and paper process water

Electroplating wastewater

Processes subject to corrosion and wear (

>"Current Topics: Slurry Self-Priming" )

Other

Wear resistant high Cr steel casting

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.

YST Alloy lineup
Metallographic
structure Material Characteristic, Use Handling liquid (Our supply record) Austenite YST30

Austenite stainless steel with improved corrosion resistance and wear resistance

Gypsum slurry

YST40

Austenite high alloy stainless steel with improved corrosion resistance such as acid resistance and alkali resistance

Sulfuric acid / hydrochloric acid wastewaters

Duplex YST130A Duplex stainless steel having high corrosion resistance and wear resistance.
Mainly used for pump casings

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

YST130C

Duplex stainless steel with improved wear resistance than YST130A.
Mainly used for pump impellers

Gypsum slurry, Lime slurry, Zinc slurry, SiO2 slurry, Sulfuric acid slurry

YST130N

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

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

High chromium CCR10

High chromium steel casting with superior wear resistance.
Used for pump components

Water containing neutral scales, Gypsum slurry, Lime slurry, Magnesium hydroxide slurry

Note: YST30 can be replaced by YST130N.


(For reference) We also manufacture the following JIS materials.

Metallographic
structure Material Characteristic, Use Handling liquid (Our supply record) Austenite SCS13

General corrosion resistance
(SUS304 equivalent)

Industrial water, Pure water, Drainage (acid, alkali), Miscellaneous wastewater, Pulp, Caustic soda

SCS14

Improved corrosion resistance and pitting corrosion resistance than SUS 304
(SUS316 equivalent)

Seawater, Pulp raw material, Chlorine-mixed water, Activated sludge filtrate, Factory wastewater, Acidic wastewater, Concentrated sulfuric acid

SCS16

Improved grain boundary corrosion resistance than SUS 316
(SUS316L equivalent)

Ammonia, Wastewater containing surfactant, Hot water containing salt, Sulfuric acid solution

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 Duplex SCS10 Improved pitting corrosion resistance and crevice corrosion resistance than SUS 329J1
(SUS329J3L equivalent)

Wastewater containing slurry, Flue gas treatment tower circulating water, Salt water, NaCl / Na2SO4 slurry

SCS11

Acid resistance, pitting corrosion resistance and high strength
(SUS329J1 equivalent)

Brine

Corrosion resistance, Wear resistance

Fig.1 All-surface corrosion resistance

Fig.2 Pitting corrosion resistance

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.

Fig.3 Corrosion resistance and wear resistance

Fig.4 Wear resistance (Rate of wear, counting the wear of SCS14 by 20% slurry as 100)

Fig.5 Corrosion resistance and wear resistance (Rate of wear, counting the wear of SUS316 by 5% slurry as 100)

YST130N is more suitable than YST130A for highly corrosive slurry liquid.


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