Sharpy test values of ASME materials 3

[Xianglu]

We are currently using normal carbon materials (not LT). However, there is an ISO V-test value requirement of not less than 27 J at a temperature of -15 deg C. Could anyone advise do the following ASME materials meet this requirement?
SA105
SA106 B
SA226 WCB
SA516 Gr 70
SA193 B7
Or do I have to use LT materials?
Thanks in advance.

 

[Xianglu]

One more question:
Even with LT materials (A 516 70; A 352 LCB; 350 LF2; A420 WPL6; A333 6, ASME standards only have V-test values at much lower temperature (~-50 deg) with lower sharpy value (~ 17 J). How do I ensure that they meet PED 27 J requirement at higher temperature (-12 deg C in this case), if the mill does not provide such test temperature report?

 

[metengr]

Typically, as the Charpy impact test temperature increases, the measured impact energy (J) also increases. Thus, at -50 deg C if you have a Charpy impact energy value of 17J, at -12 deg C, the energy will be substantially higher then this value. There should be no problem with these materials.

If you need a specific Charpy impact test value at -12 deg C to show conformance with PED 27, you will have to have the mill test at this temperature.

 

[SJones]

PD 5500 would allow you to increase the achieved Charpy energy by 1.5J for every 1 deg C elevation in temperature from the test temperature (but PD 5500 is not the governing standard!). If you have quality suppliers, they will be easily exceeding the 27J requirement even at -46 deg C and things can only get better at -12 deg C. Your supplying mills must have inspection records to ISO 10474 3.1.B or EN 10204 3.1.B wherein they have to show the achieved Charpy values and they should be able to present you some examples from previous orders. If they can't, go elsewhere!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/