Carbide refers to iron carbide or alloy carbides that are part of the steel microstructure. If they are not uniformly dispersed throughout the part, then there is heterogeneity, which would lead to variation in properties and performance. This would be measured from multiple images taken with a metallurgical microscope on a specially prepared metallographic specimen.
Thanks for your reply CoryPad. is there any standard for determining carbide heterogeneity? we received some materials(1.2436 tool steel) certificate that expresses carbide heterogeneity like this: carbide heterogeneity: 46 (Böhler). I wanna know whats the meaning of the number 46 and how the heterogeneity is classified.
There is a standard that has been used in the United States for decades to rate carbide distribution in steel alloys in terms of hook, network, and streak. It was produced by Latrobe. You can view it here:
@ Hartun,
Are you referring to a Powder metallurgical compact tool steel product? If yes, then the heterogeneity of carbide particles, their sizes and distribution must be being described. I do not think, it happens in melt samples.
Please come back, if you have a better description.
"Even,if you are a minority of one, truth is the truth."
You can rate carbide hetrogeneity for tool steels using NADCA 207-2015. The spec includes charts for microsegragation and banding at 50X and acceptable and unacceptable microstructures at 500X. This rating system can be applied even if the product was not ordered as a NADCA-grade alloy.
