British Standard Special Purpose Austenitic Cast Iron Grades
The range of British standard special purpose austenitic cast iron grades covers grades 500-600. These grades provide benefits such as wearing and abrasion resistance for use in industries that see frequent or regular wear, such as automotive, machine parts, and valves.
Grade 500
The Grade 500 British standard for special purpose austenitic cast iron has the chemical composition at (mass fraction, %):
Carbon: 0.30-0.60
Silicon: 0.60 max
Manganese: 0.50 max
Phosphorus: 0.050 max
Sulphur: 0.025 max
Chromium: 1.50 min
Nickel: 0.50-1.30
Molybdenum: 0.20-0.40
Other: 0.50 max
Extraneous material: Trace
Grade 500 is composed mainly of iron, silicon, and carbon and is strengthened primarily by the alloying elements of chromium and nickel. Grade 500 is the most common of the range and is suitable for a variety of general engineering and automotive applications, such as tail flasks, valve bodies, and brake discs.
Grade 501
Grade 501 is the same as Grade 500, but with a slightly higher carbon content for additional strength. The chemical composition for Grade 501 (mass fraction, %) is:
Carbon: 0.60-0.80
Silicon: 0.60 max
Manganese: 0.50 max
Phosphorus: 0.050 max
Sulphur: 0.025 max
Chromium: 1.50 min
Nickel: 0.50-1.30
Molybdenum: 0.20-0.40
Other: 0.50 max
Extraneous material: Trace
This grade is suitable for more complex and extreme conditions such as parts that are subject to vibration, high temperature, and high abrasion.
Grade 502
The Grade 502 grade of British standard special purpose austenitic cast iron has a slightly higher carbon content and is often used in more extreme conditions. The chemical composition (mass fraction, %) of Grade 502 is:
Carbon: 0.80-1.00
Silicon: 0.60 max
Manganese: 0.50 max
Phosphorus: 0.050 max
Sulphur: 0.025 max
Chromium: 1.50 min
Nickel: 0.50-1.30
Molybdenum: 0.20-0.40
Other: 0.50 max
Extraneous material: Trace
Grade 502 is suited for use in even more extreme conditions, such as for parts that need to be resistant to fire and high temperatures, and for use in construction.
Grade 600
The Grade 600 grade of British standard special purpose austenitic cast iron is the highest grade and is used for very special applications that require high-strength and superior corrosion resistance. The chemical composition (mass fraction, %) of Grade 600 is:
Carbon: 0.50 max
Silicon: 0.80-1.30
Manganese: 0.50 max
Phosphorus: 0.050 max
Sulphur: 0.050 max
Chromium: 3.00-4.00
Nickel: 2.00-3.00
Molybdenum: 0.20-0.40
Other: 0.50 max
Extraneous material: Trace
Grade 600 is often used in more extreme conditions, such as in cases where exceptionally high wear and abrasion resistance is required.
Conclusion
The range of British standard special purpose austenitic cast iron grades covers grades 500-600 and provides hours of wear and abrasion resistance where high strength and superior corrosion resistance are desired. Grade 500 is the most common grade but Grade 501 and Grade 502 are used for more extreme conditions, while Grade 600 is reserved for very special applications in which exceptionally high wear and abrasion resistance is required.