HT300 casting material - normalisation and tempering

[dogbural]

Hi,

One of the requirements in the casting drawing is that after casting with HT300 material (equivalent to GC40), the casting shall be normalised and tempered.
I guess this is due to increase tensile strength.

Q1. Is it a common practice in casting industry?
Q2. Is it really possible to do normalisation and Temper together or one another?

 

[mfgenggear]

OP
I researched the material and searched for material and heat treat data sheets.
And found zero heat treat data.
I would recommend to communicate with the manufactory m & p lab. It has high heat resistance and corrosion resistance. Normalize may be detrimental.
It

 

[MFAMET]

ASM Handbook, "Heat Treatment" covers the approaches how to perform the heat treatment for all cast irons, such as grey, white, malleable and other cast irons.

The normalization is performed to restore the altered properties of grey cast iron to the as-cast
iron. The normalized temperature is 1600-1700F for one hour per inch at the thickest section. After removed from the furnace air cooling should be followed.
Tempering is only applied for the hardened (quenched)cast iron and it is apparent not part of normalization process.