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1429 views
03:57 Mar-30-2005

Charlie Toh

Consultant, NDT LEVEL 3
Singapore,
Joined Mar 2005
3
IQI Sensitivity

Part Material : Inconel 718
Part Thickness : 0.070inch
Part Desc.: Stator Vane
I have xrayed a vane, and the IQI, placed on a Inco shim of equal thickness beside the part, is a Pratt & Whitney hole type penetrameter with a .05 designation ( used for part thicknesses from 0.050 to 0.099inch ), of Inco material. The thickness of the IQI is 0.001inch and the 1T,2T and 4T holes are of diameters 0.010inch, 0.020inch and 0.040inch respectively.
The radiographic acceptance criteria does not permit pores larger than 0.006inch in diameter. I could see the outline of the IQI, placed on the shim, and the 1T hole, on the radiograph. Is this radiographic sensitivity adequate to meet the acceptance criteria requirements?



 
01:11 Apr-01-2005

S.V.Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
782
Re: IQI Sensitivity ----------- Start Original Message -----------
: Part Material : Inconel 718
: Part Thickness : 0.070inch
: Part Desc.: Stator Vane
: I have xrayed a vane, and the IQI, placed on a Inco shim of equal thickness beside the part, is a Pratt & Whitney hole type penetrameter with a .05 designation ( used for part thicknesses from 0.050 to 0.099inch ), of Inco material. The thickness of the IQI is 0.001inch and the 1T,2T and 4T holes are of diameters 0.010inch, 0.020inch and 0.040inch respectively.
: The radiographic acceptance criteria does not permit pores larger than 0.006inch in diameter. I could see the outline of the IQI, placed on the shim, and the 1T hole, on the radiograph. Is this radiographic sensitivity adequate to meet the acceptance criteria requirements?
------------ End Original Message ------------

I feel you should fabricate a special IQI for the special needs in this case. A special hole of 0.005 inches should be drilled and that should be seen. If coventional radiography cannpt give that sensitivity, microfocal radiography would be probably the right solution.

Swamy




 
01:33 Apr-02-2005
Buddy
Re: IQI Sensitivity I believe you are missing the point. The intent of using an IQI is to verify the adequacy of the RT technique to discern thickness changes (Density) in the item being examined. Thus, if you can resolve the 1T hole, your technique is capable of imaging a 1% change in the material. The RT procedure should specify which sensitivity is required: 1T, 2T or 4T. The number represents 1%, 2% or 4% of the IQI thickness.

As to acceptance criteria, the visible hole is not to be used to accept or reject a part. The acceptance standard specifies what is not acceptable. If you can see the discontinuity, and it exceeds the acceptance standards, the the part should be either rejected or sent for additional evaluation.

Hope this helps.
--------- Start Original Message -----------
: Part Material : Inconel 718
: Part Thickness : 0.070inch
: Part Desc.: Stator Vane
: I have xrayed a vane, and the IQI, placed on a Inco shim of equal thickness beside the part, is a Pratt & Whitney hole type penetrameterwith a .05 designation ( used for part thicknesses from 0.050 to 0.099inch ), of Inco material. The thickness of the IQI is 0.001inch and the 1T,2T and 4T holes are of diameters 0.010inch, 0.020inch and 0.040inch respectively.
: The radiographic acceptance criteria does not permit pores larger than 0.006inch in diameter. I could see the outline of the IQI, placed on the shim, and the 1T hole, on the radiograph. Is this radiographic sensitivity adequate to meet the acceptance criteria requirements?
------------ End Original Message ------------




 
06:14 Jun-13-2005

khaja

Engineering
ST AVIATIONS SERVICES COMPANY LTD,
Singapore,
Joined Jan 2002
6
Re: IQI Sensitivity

Radiography sensitivity and acceptance standard are two different things. While achieving radiographic sensitivity does nt means all discontinuties are recorded on film however, achieving a particular sensitivity is important to validate the quality of radiograph. The acceptance criteria shall always be what is accepted and what is rejected by stds/spec.

To another part of your question, achieving 1% sensitivity eans your radiograph reveal discon equal to or greater than 1% of part thickness.

wish you good times


 


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