Qualified thickness for base metal & weld metal for PQR

Thickness range qualified for base metal & weld metal is given as per table QW-451.1, ASME Sec. IX

Example:

If I have to weld 130 mm thick plate with only SMAW process, then for PQR, you can use the following base metal thickness and weld metal for qualification. 

Base metal thickness : above 38 mm thickness, qualifying range of BM is 5-200 mm. So you can take 40 mm thick plate. 

Deposited Weld metal thickness : above 19 mm thickness of weld metal deposited, qualifying thickness is upto 200 mm. So you can weld upto 20 mm. 

So, you can take base metal 40 mm thick and deposit weld metal upto 20 mm for PQR. 

keep reading, happy welding 

KP Bhatt  

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Fillet Weld Break Test / Fracture Test

The fillet weld break test is a mechanical testing process for examining the root penetration in a destructive manner. While the macro-etch test provides penetration depth of the specimen in a given area, the fillet weld break test examines the root penetration for the entirety of the specimen. The test includes the potential failure points of the weld which are the stop and restart of the weld.

To pass the break test, the specimen must bend flat upon itself without fracturing. Should fracture occur, the fractured surface shall show no evidence of cracks or incomplete root fusion, and the sum of the lengths of inclusions and porosity visible on the fractured surface shall not exceed 3/8 in (10 mm) in Figure as shown below,

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Break Teat Procedures 

  1. Cut 25 mm off of each end of the 150 mm specimen resulting in a 100 mm specimen (the 25 mm Specimens will be used for the macro etch test)
  2. Be sure the table is clear of all obstructions
  3. Place the T joint on an angle with the weld metal face up as shown in Figure, subjecting the root of the weld to tensile stress
  4. Drop the press on the material until the specimen breaks or lays flat on itself
  5. Examine the results

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Macro-etch

The macro-etch test will be utilized to gain a penetration reading of each test specimen.  The macro-etch test allows for the observation of the weld penetration profile by sectioning the weldment.  The profiles will be observed for the effective throat depth.  The information will be recorded to verify the acceptance and integrity of each weld performed from a penetration stand point. The results will be compared with the results from the mechanical testing processes (i.e. break test) to help define the failure limits of various penetration depths.