GB/T 43409-2023Metallographic examination of carbon steel and low alloy steel castings for general engineering and sturctural purposes (English PDF)

Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020 "Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents".

1 Scope

This document specifies the selection and preparation of metallographic examination specimens, metallographic structure inspection, grain size determination, non-metallic inclusion inspection, inspection of carbon steel and low alloy steel castings, as well as the inspection report, for general engineering and structures.

This document is applicable to the metallographic examination of carbon steel and low alloy steel castings for general engineering and structures; the metallographic examination of carbon steel and low alloy steel castings for other engineering and structures can make reference to this document.

2 Normative references

The contents of the following documents constitute the essential terms of this document through normative references in the text. Among them, for dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 5611 Foundry terminology

GB/T 6394-2017 Determination of estimating the average grain size of metal

GB/T 7232 Metal heat treatment - Terminology

GB/T 13298 Inspection methods of microstructure for metals

GB/T 20566 Terminology of steel and alloy

3 Terms and definitions

The terms and definitions as defined in GB/T 5611, GB/T 7232, GB/T 20566, as well as the following terms and definitions, apply to this document.

4 Selection and preparation of specimens

4.1 Metallographic specimens shall be cut from castings or mechanical properties test blocks.

4.2 The preparation of metallographic specimens shall comply with the provisions of GB/T 13298. The changes in the structure shall be prevented during the cutting and preparation of specimens. The surface of the specimen inspection surface shall be kept smooth before etching, without scratches and other grinding and polishing defects.

4.3 The etching of metallographic specimens should be carried out with a mixture of 2% ~ 6% nitric acid and anhydrous ethanol (2 mL ~ 6 mL nitric acid + 100 mL anhydrous ethanol).

5 Metallographic structure inspection