Ferrite inclusion test

[payaam2000]

Dear all

We are responsible for a pressure vessel with inconel625 overlay and C.S base metal.

our main client has requested from us to perform ferrite inclusion test after machining.

would you please explaine what is ferrite inclusion test and why it is needed for cladded productions.

tanks in advanced

 

[Tony1t]

payaam2000;
Austenitic, Duplex, Super-duplex stainless steels require adequate proportion of ferrite in the product to obtain acceptable corrosion resistance and strength and especially resistance to Stress Corrosion Cracking .

 

[weldstan]

Assuming that this requirement refers to the machined removal of Alloy 625 overlay prior to making the strength welds in the carbon steel; if so, it assures that the carbon steel weld metal will not be diluted with alloy 625 and create a crack sensitive alloy deposit. In this case, all you will see with the test is etched carbon steel.