Charpy test for grade F51/2205 4

[zulsaid]

I have received material F51 that carried out charpy test at -46 celcius(pass) but our customer request to carried out at -50 celcius. Surprisingly the value is very far different,
temp Joule
-46 celcius 56,71,76
-50 celcius 8,10,12

Anybody can explain this?

 

[metengr]

Was the same orientation of Charpy specimen removal followed for both tests?

 

[zulsaid]

metengr,

The specimen test is 10x10x55mm. cut at longitudinal same for both test. Here I give you more detailed info:

Grade F51:

Dia. Size 80mm:
temp Joule
-46 celcius 56,71,76
-50 celcius 8,10,12

Dia Size 90mm:
temp Joule
-46 celcius 300,300,300
-50 celcius 54,80,102

Dia Size 100mmm:
temp Joule
-46 celcius 165,186,176
-50 celcius 34,12,38

Can you explain what is the problem?

 

[zulsaid]

metengr,

for your info, -46C is tested by our supplier, while -50C is tested by us.

 

[zulsaid]

metengr,

Is 1.4462 UNSS31803=F51? Is the bar product is also claim as forging product? please help

 

[SJones]

The difference may lie in the fact that your supplier tested a nicely manufactured and heat treated test blank whereas you are testing the actual product!!! A 4 deg C difference in test temperature should not induce the marked difference in Charpy energy that you are observing. It looks like you may have what is termed a 'dispute' looming with your supplier.

For ASTM A182, bar stock does not constitute a forging. Whether the same applies under DIN/EN, I'll leave that to someone else who has the standard.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[stanweld]

Steve has hit the nail on the head. The manufacturer tests per the ASTM Specification, most likely on seperately forged test blanks per 8.2 of A-182. He may also "select" the production forging for testing. I've seen dramatic changes in properties from samples made from our purchased production forgings versus manufacturers'results.

 

[metengr]

Better be careful here and read the fine print... 4.4 of ASME SA 182/ASTM A 182,

4.4 The material forged shall be as close as practicable to the specified shape and size. Except for flanges of any type, forged OR rolled bar may be used without additional hot working for small cylindrically shaped parts within....

One can manufacture forged bar and meet this specification.

 

[zulsaid]

From my investigation, I found on the supplier's report:
I suspect the heat treatment maybe goes wrong,

OD80mm: Holding time =2hrs
OD90mm: Holding time =2.5hrs
OD100mm: Holding time =2hrs
OD114mm: Holding time =3hrs,70J at -50C(same supplier)

Since OD80mm and OD90mm not pass, while OD100mm and OD114mm pass, so may I conclude that the heat treatment not proper causing the failure.

 

[SJones]

Metengr - true (as per 5.4 of A182) but then one has to cross over to A 403 and bars themselves are covered by A739. It looks as though the supplier has played the 'get out of forging jail' card for diameters up to NPS 4 (114 mm) under ASTM A182/A961; however, we still have not clarified what exact specification the parts have actually been ordered to, and what the parts actually are.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04