Document: NRC Regulatory Guide
Document ID: c6e354c2-cc83-4d3d-b01b-b43865ccdac6
Document Type: regulatory_guide
Title: Control of Ferrite Content in Stainless Steel Weld Metal + HISTORY - HISTORY DG-1279 , Proposed Revision 4, published 09/2012 (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1202/ML12024A004.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.31
CFR Part: 
CFR Title: 

Content:
g specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required. DG-1279, Page 2 This regulatory guide contains information collection requirements covered by 10 CFR Part 50 that the Office of Management and Budget (OMB) approved under OMB control number 3150-0011. The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number. This regulatory guide is a rule as designated in the Congressional Review Act (5 U.S.C. 801- 808). However, OMB has not found it to be a major rule as designated in the Congressional Review Act. B. DISCUSSION Inspection of some welds in austenitic stainless steel components of nuclear reactors has revealed the presence of microfissures. Further investigations related the presence of the microfissures to the low delta ferrite content of the deposited weld metal. Since microfissures in austenitic welds may have an adverse effect on the integrity of components, the control of weld deposits to ensure the presence of delta ferrite in these welds is advisable. To achieve this control, the original version of this guide, Safety Guide 31, “Control of Stainless Steel Welding,” issued August 1972 (Ref. 2), provided guidance to test production welds. This guidance was retained in Revision 1 of the Safety Guide, which was issued June 1973 as Regulatory Guide 1.31, “Control of Ferrite Content in Stainless Steel Weld Metal (Ref. 3) Because licensees and other representatives of the nuclear industry believed that adequate control of filler metal ferrite content would consistently provide sound weld deposits with an absence of microfissures, the American Society of Mechanical Engineers (ASME), the American National Standards Institute (ANSI), and the NRC formed a cooperative study group to