本文件规定了以下方法和装置: -通过焊接金属样品和标准永久磁铁之间的吸引力，测量主要为奥氏体和双铁素体奥氏体不锈钢[1]焊接金属中的δ铁素体含量，表示为铁素体数（FN）； -手工金属电弧焊条标准焊盘的制备和测量。对于生产焊缝的铁素体测量以及其他工艺（如钨极气体保护焊、气体保护金属极电弧焊和埋弧焊）的焊缝金属，也建议采用通用方法（在这些情况下，应确定焊垫的生产方式）； -校准其他仪器以测量FN。 本文件中规定的方法适用于焊接状态下的焊接金属，以及热处理后导致铁素体完全或部分转变为任何非磁性相的焊接金属。改变铁素体大小和形状的奥氏体化热处理改变铁素体的磁响应。 本方法不适用于测量铸造、锻造或锻造奥氏体或双铁素体的铁素体含量- 奥氏体钢样品。 [1] 术语“奥氏体-铁素体（双相）不锈钢”有时用来代替“双相铁素体-奥氏体不锈钢”。

This document specifies the method and apparatus for: — the measurement of the delta ferrite content, expressed as Ferrite Number (FN), in largely austenitic and duplex ferritic-austenitic stainless steel[1] weld metal through the attractive force between a weld metal sample and a standard permanent magnet; — the preparation and measurement of standard pads for manual metal arc covered electrodes. The general method is also recommended for the ferrite measurement of production welds and for weld metal from other processes, such as gas tungsten arc welding, gas shielded metal arc welding and submerged arc welding (in these cases, the way of producing the pad should be defined); — the calibration of other instruments to measure FN. The method laid down in this document is intended for use on weld metals in the as-welded state and on weld metals after thermal treatments causing complete or partial transformation of ferrite to any non-magnetic phase. Austenitizing thermal treatments which alter the size and shape of the ferrite change the magnetic response of the ferrite. The method is not intended for measurement of the ferrite content of cast, forged or wrought austenitic or duplex ferritic-austenitic steel samples. [1] The term "austenitic-ferritic (duplex) stainless steel" is sometimes applied in place of "duplex ferritic-austenitic stainless steel".