GB/T 20078-2023Copper and copper alloys—Forgings (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules for Standardization Documents" drafting.

This document replaces GB/T 20078-2006 "Copper and Copper Alloy Forgings". Compared with GB/T 20078-2006, except for structural adjustment and apart from editorial changes, the main technical changes are as follows:

a) Added the scope of application of the document (see Chapter 1, Chapter 1 of the 2006 edition);

b) Changed some terms and definitions (see Chapter 3, Chapter 3 of the 2006 edition);

c) The content related to "material" and "material status" has been deleted (see 4.1 and 4.2 of the 2006 edition), and the content of "material grade" has been added (see 4.1);

d) Deleted references to EN standards (see 4.1.3, 4.2, 8.3, 8.6, 9.1, 9.2, Table 1 of the 2006 edition);

e) The "Material Group" column has been added, some material grades have been deleted, and material grades and As and P elements have been added (see Table 1 to Table 8, Table 1~Table 8 of the 2006 edition);

f) Deleted "Table 9 Material Groups and Categories" (see Table 9 of the 2006 edition);

g) Added Table 9 "Hardness of forgings in material group I" and Table 10 "Hardness of forgings in material group II" (see Table 9, Table 10);

h) Changed the requirements for ordering documents (see Chapter 5, Chapter 5 of the 2006 edition);

i) The requirements for mechanical properties, electrical properties, and dezincification resistance have been changed (see 6.2, 6.3, 6.4, 6.2, 6.3, 6.4 of the 2006 edition);

j) Delete the requirement of residual stress (see 6.5 of the 2006 edition);

k) Added requirements for heat treatment and stress corrosion resistance (see 6.5, 6.6);

l) The requirements for volume resistivity and mass resistivity have been deleted, and the electrical performance requirements for Cu-HCP have been added (see Table 11, 2006 edition Table 13);

m) Changed the general requirements in "Tolerances of Die Forgings", the dimensional tolerances in the die cavity and across the parting line (see 6.7, 2006 edition 6.6);

n) Some values of die forging tolerances of material group I, material group II and material group III have been changed (see Table 12~Table 14, 2006 edition Table 14~Table 16);

o) Added Table 15 "Tolerances for Die Forgings of Material Group I (Polygonal Shape)" (see Table 15);

p) The regulations on "Tolerances for Hollow Die Forgings" have been changed, and the illustration of hollow die forgings has been divided into the center line of the hole consistent with the forging direction and in the two cases perpendicular to the forging direction, the tolerance values of hollow die forgings have been changed (see 6.8, Figure 14, Figure 15, Table 17, 2006 Version 6.7, Figure 14, Table 18);

q) The general requirements, dimensional tolerances, and flatness tolerances in "Free Forging Tolerances" have been changed (see 6.9, 6.8 of the 2006 edition);

r) The requirements for special surfaces have been added to the surface quality (see 6.10, 6.9 of the 2006 edition);

s) Changed the sampling requirements for hardness test, stress corrosion resistance test, dezincification resistance test and electrical performance test (see 7.3, 2006 edition 7.3);

t) Change the provisions of the test methods for hardness test, dezincification resistance test and stress corrosion resistance test (see 8.3, 8.5, 8.6, 2006 edition 8.2, 8.5, 8.6 of the 2006 edition), the content of the tensile test method was deleted (see 8.3 of the 2006 edition), and the content of the chemical composition test method was added content (see 8.2);

u) Changed "Description of Conformity and Testing Documents" to "Certificate of Conformity", and changed the content of this chapter (see Chapter 9, 2006 Chapter 9 of the annual edition).

1 Scope

This document specifies the identification, ordering information, technical requirements, sampling, test methods, qualification certificates, and standards for copper and copper alloy forgings. marking, labeling and packaging.

This document applies to the manufacture of copper and copper alloy forgings.

2 Normative references

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

GB/T 231.1 Brinell hardness test for metallic materials - Part 1: Test method

GB/T 1804-2000 General tolerances Tolerances of linear and angular dimensions without tolerances

GB/T 5121 (all parts) Methods for chemical analysis of copper and copper alloys

GB/T 8541 Forging Terminology

GB/T 10119 Dezincification Corrosion Resistance Determination of Brass

GB/T 10567.2 Test method for residual stress of copper and copper alloy processed materials Ammonia fumigation test method

ISO 1811-2 Selection and preparation of test pieces for chemical analysis of copper and copper alloys - Part 2: Sampling of processed products and castings

3 Terms and Definitions

The following terms and definitions defined in GB/T 8541 apply to this document.

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