Document: NRC Regulatory Guide
Document ID: 44b58049-ac63-457b-a075-ef162b34cb70
Document Type: regulatory_guide
Title: Materials code case Acceptability - - ASME Section III, Division 1 (Rev. 31)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740365.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.85
CFR Part: 
CFR Title: 

Content:
ls to brittleness and stress corrosion cracking. Certain applications may exist where a UTS value of up to 190 Ksi could be con sidered acceptable for a material and, under this condi tion, the Design Specification should specify impact testing for the material. For these cases, it should be de monstrated by the applicant that (1) the impact test re sults for the material meet code requirements and (2) the material is not subject to stress corrosion cracking by virtue of the fact that (a) a corrosive environment is not present and (b) the component that contains the ma terial has essentially no residual stresses or assembly stresses, and it does not experience frequent sustained loads in service. In the last sentence of paragraph 5.3, reference should be made to paragraph 4.5.2.2, "Alter nate Atmosphere Exposure Time Periods Established by Test," of the AWS D.1.1 Code for the evidence pres ented to and accepted by the Authorized Inspector con cerning exposure of electrodes for longer periods of time. N-71-12 02-14-83 Additional Materials for Comi 02-20-84 ponent Supports Fabricated by Welding, Section III, Division 1, Class 1, 2, 3, and MC Code Case N-71-12 was acceptable subject to the following condition in addition to those conditions spe cified in the Code Case: The maximum measured ulti mate tensile strength (UTS) of the component support material should not exceed 170 Ksi in view of the sus ceptibility of high-strength materials to brittleness and stress corrosion cracking. Certain applications may ex ist where a UTS value of up to 190 Ksi could be consid ered acceptable for a material and, under this condition, the Design Specification should specify impact testing for the material. For these cases, it should be demon strated by the applicant that (1) the impact test results for the material meet code requirements and (2) the ma terial is not subject to stress corrosion cracking by vir tue of the fact that (a) a corrosive environment is not present and (b)