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Alloy Data Sheet – Pliant25 High Chrome White Iron

Posted by Penticton Foundry on January 26, 2016

Pliant25 ASTM A532 Class III Type A

Pliant25 is a unique high chrome white iron that has been perfected by Penticton Foundry.  Our engineered chemistry together with our proprietary heat treatment allows us to soften this alloy to the point where we can then drill and tap holes, as well as broach keyways.  After machining, we can heat treat the casting to harden this alloy to a minimum of 600 BHN.  Dimensions are calculated to allow for dimensional changes during the hardening process.  For very tight tolerances, final machining can be done.pump-casing-made-of-chrome-white-iron.jpg

This alloy has very good abrasion resistant properties, especially against gouging, grinding and scratching.  Pliant25 is a hypoeutectic structure consisting of very hard primary and secondary carbides in a matrix of martensite.  The volume of carbides will be slightly lower than our standard 25% High Chromium Alloy; but this is necessary to be able to perform the machining operations mentioned above. 

Composition
The chemical composition of this alloy is proprietary.

Physical and Mechanical Properties (from the Abrasion Resistant Handbook)

Density lb/in3 (g/cm3)

0.26 (7.6)

Thermal Conductivity   Btu/hr·ft·F (W/m·K)

8.6-17.3 (15-30)

Specific Heat at 70F  Btu/lb·F (J/Kg·k)

0.119

Coefficient of Thermal Expansion Ɛ/F(Ɛ/C)X106 average between 70-1112F

7.2 (13)

Melting Temperature (F)

2300 F

Compressive Strength Ksi (MPa)

429 (2960)

Transverse Strength Ksi( MPa)

136 (938)

 

 


Typical Hardness

 

Brinell (depends on thickness)

As-Cast

400-500

Annealed

250-350

Hardened

600-650


Applications
This alloy can be used anywhere our standard 25% High Chromium alloy is used.  However, it is most commonly used for components that require extensive machining; typically, castings that become part of a larger assembly.  Examples are: volutes, impellers, suction and motor-side liners, parts for hydraulic fracturing (impellers, housings, blender tubs, etc.) and thin-section parts.

Designing
The Pliant25 alloy has an inconsistent tensile strength.  For design questions please contact Penticton Foundry.

Corrosion Properties
The Pliant25 alloy has good corrosion resistance for the majority of slurries it will be exposed to.  In severe applications (like flue gas desulfurization) consider using a 28% – 30% Cr alloy.

Processing

  • Casting section thicknesses of up to 3 inches (75mm) are common
  • Annealing allows drilling/tapping and broaching
  • Subsequent hardening provides excellent abrasion resistance
  • Penticton Foundry can offer machining of Pliant25
  • Welding is not recommended on Pliant25

Reference Specifications
ASTM A532 Class III Type A

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