B31.3 PQR Impact test exemptions 1

[WE91]

I would like to get the groups opinion on low temperature service requirements of b31.3. For the sake of this discussion I would like to leave out stress ratio exemptions so we can clearly discuss if impacts are required assuming at the min temps. listed in table A1.

Scenario 1

MDMT -20F, BM Thickness is 1.5" A333 GR. 6 and the consumable is ER70S-2 (pre impact tested at -20F in accordance with SFA 5.18) do low temp service restrictions apply requiring PQR impacts and invoking supplementary variables OF Section IX?

Scenario 2

MDMT -50F, BM Thickness is 1.5" A333 GR.6 and the consumable is ER7018-1 (pre impact tested at -50F in accordance with SFA 5.1) do low temp service restrictions apply requiring PQR impacts and invoking supplementary variables of section IX?

Scenario 3

MDMT -20F, BM Thickness is .5" on Curve B and the consumable is ER70S-2 (pre impact tested at -20F in accordance with SFA 5.18) do low temp service restrictions apply requiring PQR impacts and invoking supplementary variables OF Section IX?

Again trying to keep the conversation away from stress ratio exemptions, and focus on just the info stated above.

Code addition would be 2018 or 2022 ( i dont think there is a difference related to this discussion.)

 

[fleischfresser]

This discussion can only be based on ASME B31.3 Edition 2020 or later as there are several changes to the toughness testing requirements with Edition 2020.

Basic for the Evaluation:
ASME B31.3 Ed. 2020

323.2.2 Lower Temperature Limits, Listed Materials
……
(d) Impact testing of the base metal is not required if the design minimum temperature is warmer than or equal to the temperature listed in the Min. Temp. column of Table A-1, or Table A-1M, except as provided in Table 323.2.2, Box A-4(a) for austenitic stainless steel base material. …,

Base metal Scenario 1 and 2:
Min. Temp. column of Table A-1: For A333 Gr. 6 Table A-1: -50° F

(e) For carbon steels with a letter designation in the Min. Temp. column of Table A-1 or Table A-1M, the minimum temperature is defined by the applicable curve and Notes in Figure 323.2.2A. If a design minimum temperature–thickness combination is on or above the curve, impact testing exemption requirements described in (d) apply.

Base metal Scenario 3:
Min Temp. 0.5” thick curve B material: -20 °F (acc. Fig. 323.2.2A or Table 323.2.2A)

Table 323.2.2 Requirements for Low Temperature Toughness Tests for Metals
Column A: Design Minimum Temperature at or Warmer Than Minimum Temperature in Table A-1, Table A-1M, or Figure 323.2.2A or as Described in Para. 323.2.2(h):
Listed Materials, Line 3 Other carbon steels; low and intermediate alloy steels; and ferritic, martensitic, and duplex stainless steels:
(a) Base Metal: A-3 (a) No additional requirements
(b) Weld Metal: A-3 (b) The weld metal of the welding procedure qualification test coupon shall be impact tested at or below the design minimum temperature when that temperature is less than −18°C (0°F), except when Note (3) or Note (4) is satisfied; impact testing of the weld metal is not required when the classification of the welding consumables according to the filler metal specification requires impact testing at or below the design minimum temperature.

Note (4) is due to the thickness not applicable.
Note (3) deals with exemption by the ratio and will be not considered.

Filler Metal Scenario 1 and 3:
ASME II-C SFA-5.18:
ER-70S-2:
SFA-5.18 Table 4
Mechanical Property Requirements (As Welded)
Impact Strength [sup]g, h, i[/sup] (minimum average): 20 ft·lbf @ 0°F [27J @ –20°C]

Note i: Filler metal classification testing to demonstrate conformance to a specified minimum acceptable level for impact testing, i.e., minimum energy at specified temperature, can be met by testing and meeting the minimum energy requirement at any lower temperature. In these cases, the actual temperature used for testing shall be listed on the certification documentation when issued.


Filler Metal Scenario 1 to 3
ASME II-C SFA-5.1:
ER-7018-1:
SFA-5.1 Table 3
Charpy V-Notch Impact Requirements: Average, Min.20 ft·lbf at –50°F


Evaluation
Base Metal of Scenario 1 and 2:
A-333 Gr.6 is exempted from impact testing by 323.2.2(d) and Table 323.2.2, field A-3(b)
Base Meal of Scenario 3:
Curve B base metals 0.5” are exempted from impact testing by 323.2.2(e) and Table 323.2.2, field A-3(a)

Filler metal of Scenario 1 and 3:
The filler metal is exempted from impact testing by Table 323.2.2, field A-3(b) because of Note i of SFA-5.28, Table 4


Filler metal of Scenario 2:
The filler metal is exempted from impact testing by Table 323.2.2, field A-3(a) because of the requirements of SFA-5.1 Table 3 for electrode with the designator -1 for improved toughness

Conclusion
For all Scenarios base metal and filler metal are exempted from impact testing and therefore the supplementary variables of Section IX are not applicable.


Regards - Juergen