本標準規定了鐵素體含量的測量方法。 本標準適用于奧氏體型、奧氏體-鐵素體型鉻鎳不銹鋼焊縫金屬。 本標準規定的磁性法不適用于奧氏體不銹鋼鑄件和鍛件。
1 Scope
This standard specifies the methods of measurement for ferrite content.
This standard is applicable to austenitic and austenitic-ferritic stainless steel weld metals.
The magnetic method specified in this standard is not applicable to austenitic stainless steel castings and forgings.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments (excluding any corrections) to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the standards indicated below. For undated references, the latest edition applies.
GB/T 20878 Stainless and heat-resisting steels - Designation and chemical composition
3 Terms
For the purpose of this standard, the following terms and definitions apply.
3.1
ferrite
high-temperature ferrite formed directly from the solidification and crystallization of liquid metal and retained to room temperature
3.2
Ferrite Number (FN)
standardized value selected to represent the ferrite content in austenitic and ferritic-austenitic stainless steel weld metals
3.3
primary standard
accurate non-magnetic coating made of copper on a carbon steel substrate with a carbon content of less than 0.18%, plated with hard chrome and polished, each of which is marked with the international FN value of an equivalent magnetic weld metal, and which is applicable to the calibration of measuring instruments based on standard magnetic attraction, such as the Mange-Gage
3.4
secondary standard
specimen of welding deposited metal or similarly deposited metal structure made according to standard procedures, of which the FN value is determined by Mange-Gage calibrated with primary standard for periodic calibration of ferrite content measuring instruments by magnetic method
Foreword i
1 Scope
2 Normative references
3 Terms
4 Magnetic method
4.1 General principle
4.2 Measurement of shielded metal arc welding deposited metal
4.3 Preparation and measurement of other deposited metal specimens
4.4 Measurement of product welds
4.5 Calibration of measuring instruments
5 Metallographic method
5.1 Specimen preparation
5.2 Measurement
5.3 Metallographic standard pattern
6 Test report
Annex A (Informative) Reference format of test data
