25% High Chromium Alloy



The 25% Cr Alloy is the most common high chrome pure fetters poured at Penticton Foundry. This alloy has commanding abrasion resisting properties especially against gouging, grinding and scratching. 25% Cr material can be machined to experience tighter tolerances like those found in plimsoll and piping represent castings. Castings shink in this allay can be assuage and gently machined by Penticton Foundry. This 25% Cr fineness is a hypoeutectic makeup consisting of very hard feather and second-rate carbides in a array of martensite.

Composition


C

Mn

Si

Cr

Min%

2.7



24

Max%

3.0

1.3

1.0

27

 

Physical and Mechanical Properties (from the Abrasion Resistant Handbook)

Density lb/in(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

450-550

Annealed

300-450

Hardened

600-700

 

Applications
This alloy meets the requirements for many applications such as mining crusher liners, chute liners, ball mill liners (and lifter bars), slurry pumps, frac pumps, dredge pumps, impellers, oil sands applications, concrete rock crushing and recycling-machine parts (blowbars).

Designing With
The 25% Cr alloy has an inconsistent tensile strength.  

Corrosion Properties
The 25% Cr 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 8 inches (200mm) are common.

  • Full through-hardness can be obtained in 8 inch sections via alloying and heat treatment.

  • Penticton Foundry can offer machining of 25% Cr.

  • Welding is not recommended on 25% Cr.

Reference Specifications
ASTM A532 Class III Type A