ASTM A532 Class I Type A
on June 15, 2016Nickel-Chrome-High Carbon Alloy
ASTM A532 Class 1 Type A may also be called Ni-Hard 1, and is an abrasion resistant material used in applications where impact is also a concern as the wear mechanism. Good for both wet and dry applications, Ni-Hard 1 should also be considered if there are low or medium dynamic stresses. The as-cast hardness is typically 500 BHN depending on the section thickness of the casting, and it has been used in everything from cyclones in the mining industry to rollers in steel mills. Ni-Hard 1 is the least expensive wear material, but over the last 10 years many users of this material have been changing to ASTM A532 Class II and III materials. To understand why chrome white iron is so abrasion resistant, read this.
Composition
|
|
C |
Mn |
Si |
Cr |
Mo |
Ni |
|
Min% |
2.8 |
|
|
1.4 |
|
3.3 |
|
Max% |
3.6 |
2.0 |
0.8 |
4.0 |
1.5 |
5.0 |
Physical and Mechanical Properties ( reference Abrasion Resistant Handbook)
|
Density lb/in3 (g/cm3) |
0.27-0.28 (7.6-7.8) |
|
Thermal Conductivity Btu/hr·ft·F (W/m·K) |
8.6-17.3 (15-30) |
|
|
|
|
Coefficient of Thermal Expansion Ɛ/F(Ɛ/C)X106 average between 50-800F |
4.5-7.1 (8-1.8) |
|
Melting Temperature (F) |
2300 F |
|
Modulus of Elasticity (GPa) |
24-26(169-183) |
|
Transverse Strength Ksi( MPa) |
70-90 (500-620) |
|
Tensile Strength Ksi(MPa) sand cast |
40-50(280-350) |
Typical Hardness and Wear Properties
|
Casting Hardness – depending on section thickness |
550 – 690 BHN |
|
ASTM G81 Jaw Crusher Volume Loss |
1000 - 2000 mm3 (over 6x better than AR400) |
|
ASTM G65 Wear Resistance Volume Loss |
30 – 50 mm3 (~ 9x better than AR400) |
|
Slurry Jet Erosion Volume Loss 90° |
10 – 20 mm3 |
|
Slurry Jet Erosion Volume Loss 45° |
5 – 15 mm3 |
|
Slurry Jet Erosion Volume Loss 20° |
3 – 5 mm3 |
|
Relative Coriolis Erosion Resistance |
60 – 80 x better than 1018 Steel |
Applications:
This alloy meets the requirements for many applications like mining crusher liners and chute liners. It is very popular when used as augers, liners, elbows, volutes and impellers for concrete and aggregate processing
Corrosion Resistance:
Ni-Hard is not typically chosen for its corrosion resistance properties. For development of a passive film on the surface, which will impart moderate corrosion resistance, the metal matrix must have more than 12% chromium dissolved in it. Ni-Hard does not have this amount of chromium dissolved in its matrix. The higher chromium alloys (and Ni-Hard 4) have improved corrosion resistance compared to Ni-Hard 1.
Processing:
This alloy is supplied in the hardened condition.
Read: To learn about other ASTM A532 alloys, check out our chrome white iron webpage.
