46 C.F.R. § 54.25-20 Low temperature operation—ferritic steels with properties enhanced by heat treatment (modifies UHT–5(c), UHT–6, UHT–23, and UHT–82).
Title 46 - Shipping
(a) For service temperatures below 0 °F. but not below the designated minimum service temperature, steel conforming to the specifications of Table 54.25–20(a) may be used in the fabrication of pressure vessels and nonpressure vessel tanks and associated secondary barriers, as defined in §38.05–4 of subchapter D (Tank Vessels) of this chapter. The ultimate and yield strengths shall be as shown in the applicable specification and shall be suitable for the design stress levels adopted. The service temperature shall not be colder than −320 °F. Service temperature is defined in §54.25–10(a) (2). (b) The materials permitted under paragraph (a) of this section shall be tested for toughness in accordance with the requirements of UHT–6 of the ASME Code except that tests shall be conducted at the temperature specified in §54.05–6 in lieu of that in UHT–5(c) of the ASME Code. Lateral expansion in a broken Charpy V-notch specimen is illustrated in Figure 54.25–20(b) and shall be measured in accordance with the procedure outlined in ASTM A 370 (incorporated by reference, see §54.01–1). (c) The qualification of welding procedures and welders and weld production testing for the steels of Table 54.25–20(a) shall conform to the requirements of part 57 of this subchapter and subpart 54.05 except that the Charpy V-notch testing acceptance criteria shall be in accordance with UHT–6(a) (4) and (5) of the ASME Code. (d) The values of absorbed energy in foot-pounds and of fracture appearance in percentage shear, which are recorded for information when complying with paragraphs (b) and (c) of this section shall also be reported to the marine inspector or the Commandant, as applicable. (e) Except as permitted by §54.05–30, the allowable stress values may not exceed those given in Table UHT–23 of the ASME Code for temperatures of 150 °F. and below. [CGFR 68–82, 33 FR 18828, Dec. 18, 1968, as amended by CGD 73–133R, 39 FR 9179, Mar. 8, 1974; USCG–2000–7790, 65 FR 58460, Sept. 29, 2000]
Title 46: Shipping
PART 54—PRESSURE VESSELS
Subpart 54.25—Construction With Carbon, Alloy, and Heat Treated Steels
§ 54.25-20 Low temperature operation—ferritic steels with properties enhanced by heat treatment (modifies UHT–5(c), UHT–6, UHT–23, and UHT–82).
Table 54.25-20(a)------------------------------------------------------------------------ Minimum service Steel temperature, °F.------------------------------------------------------------------------A-333, 9 percent Ni, grade 8.............................. -320A-334, 9 percent Ni, grade 8.............................. -320A-353, 9 percent Ni, double normalized and tempered....... -320A-522, 9 percent Ni, NNT, Q and T, forging................ -320A-553, 9 percent Ni, quenched and tempered................ -320------------------------------------------------------------------------
