What is the most relaible and cost effective method of crack testing in Raw materials (Steel)? Our Raw material supplier is using Magnaflux testing for Raw material but he is not able to assure us 100% crack free material. What is the best type of control that will assure us 100% crack free material?

Are we talking about rod stock, wire, or a casting etc..?

Andrews said:

What is the best type of control that will assure us 100% crack free material?

Buy turned, ground and polished stock? :rolleyes:

Andrews, what shapes are you purchasing? Are you buying rod or bar stock, or beams, plates or what? There is no such thing as "perfect" surface on steel, unless it has been "surfaced" by some sort of grinding process. The standards allow for a certain depth of crack dependent upon the diameter/thickness of the material. That being said, depending on what shapes you are talking, there is eddy-current, dye-penetrant, ultrasonic and others to assess for cracks. I have found, that nothing is 100% fail-safe 100% of the time, even dye-penetrant will miss some cracks, if they have welded shut during hot-rolling.

I'm sure this wasn't the answer you were hoping for, but without a little more information, it is difficult to recommend anything specific. Good luck!

X-ray methods would be my choice where internal crack detection is a concern.

Thanks everybody for the response.

The raw material used by us is bright bars of sizes from 6mm to 40 mm HEX / Diameter.

Is X-Ray testing a cost effective method of testing raw material for crack?

Can Crack be avoided at the source itself? If so, what method should be used?

You would have to perform your own cost analysis to determine if the X-ray method is cost effective to you.
If you want to limit the possibility of cracks at the source discuss it with your supplier. He may have alternative methods of providing what you want.
As Steelmaiden said, nothing is 100%fail safe, 100% of the time.