Alloy Data Sheet – 25% High Chromium Alloy
on January 13, 2016ASTM A532 Class III Type A
The 25% Cr alloy is the most common high chrome white iron poured at Penticton Foundry. This alloy has great abrasion resistant properties especially against gouging, grinding and scratching. 25% Cr material can be machined to meet tighter tolerances like those found in pump and piping type castings. Castings poured in this alloy can be softened and easily machined by Penticton Foundry. This 25% Cr alloy is a hypoeutectic structure consisting of very hard primary and secondary carbides in a matrix 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/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 |
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. For design questions please contact Penticton Foundry.
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
