[Code of Federal Regulations]
[Title 46, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR54.05-20]

[Page 152-153]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 54_PRESSURE VESSELS--Table of Contents
 
                      Subpart 54.05_Toughness Tests
 
Sec. 54.05-20  Impact test properties for service of 0 [deg]F and below.

    (a) Test energy. The impact energies of each set of transverse 
Charpy specimens may not be less than the values shown in Table 54.05-
20(a). Only one specimen in a set may be below the required average and 
the value of that specimen must be above the minimum impact value 
permitted on one specimen only. See Sec. 54.05-5(c) for retest 
requirements.

          Table 54.05-20(a)--Charpy v-notch impact requirements
------------------------------------------------------------------------
                                      Minimum impact
                                      value required     Minimum impact
                                      for average of    value permitted
         Size of specimen             each set of 3     on one specimen
                                     specimens foot-     only of a set,
                                        pounds \1\        foot-pounds
------------------------------------------------------------------------
10 x 10 mm........................               20.0               13.5
10 x 7.5 mm.......................               16.5               11.0
10 x 5 mm.........................               13.5                9.0
10 x 2.5 mm.......................               10.0               6.5
------------------------------------------------------------------------
\1\ Straight line interpolation for intermediate values is permitted.

    (b) Transversely oriented Charpy V-notch impact specimens of ASTM A 
203 (incorporated by reference, see Sec. 54.01-1) nickel steels must 
exhibit energies not less than the values shown in Sec. 54.05-20 (a). 
Requirements for 9 percent nickel steels are contained in Sec. 54.25-
20. Other nickel alloy steels, when specially approved by the 
Commandant, must exhibit a no-break performance when tested in 
accordance with the drop weight procedure. If, for such materials, there 
are data indicating suitable correlation with drop-weight tests, Charpy 
V-notch tests may be specially considered by the Commandant in lieu of 
drop-weight tests. If the drop-weight test cannot be performed because 
of material thickness limitations (less than one-half inch), or product 
shape, or is otherwise inapplicable (because of heat treatment, 
chemistry etc.) other tests or test criteria will be specified by the 
Commandant.
    (c) Where sufficient data are available to warrant such waiver, the 
Commandant may waive the requirements for toughness testing austenitic 
stainless steel materials. Where required, austenitic stainless steels 
are to be tested using the drop-weight procedure and must exhibit a no-
break performance. Where data are available indicating suitable 
correlation of Charpy V-notch results with drop-weight NDT or no-break 
performance, Charpy V-notch tests may be specially considered by the 
Commandant in lieu of dropweight tests. If the dropweight test cannot be 
performed because of material thickness limitations (less than one-half 
inch), or product shape, or is otherwise inapplicable (because of heat 
treatment, chemistry, etc.) other

[[Page 153]]

tests and/or test criteria will be specified by the Commandant.

[CGD 73-254, 40 FR 40164, Sept. 2, 1975, as amended by USCG-2000-7790, 
65 FR 58460, Sept. 29, 2000]