GB/T 35840.4-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.35
H 46
Steels for Plastic Mould - Part 4: Pre-hardening Steel
Plate
塑料模具钢 第 4部分: 预硬化钢板
ISSUED ON: MARCH 6, 2020
IMPLEMENTED ON: OCTOBER 1, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 6
4 Order Content ... 6
5 Dimension, Shape and Weight ... 6
6 Technical Requirements ... 7
7 Test Methods ... 10
8 Inspection Rules ... 10
9 Packaging, Marking and Quality Certificate ... 11
Steels for Plastic Mould - Part 4: Pre-hardening Steel
Plate
1 Scope
This Part of GB/T 35840 specifies the terms and definitions, order content, dimension,
shape, weight, technical requirements, test methods, inspection rules, packaging,
marking and quality certificate of pre-hardening steel plates for plastic mould.
This Part is applicable to pre-hardening steel plates with a thickness of 10 mm ~ 300
mm for the manufacture of plastic moulds (hereinafter referred to as steel plates).
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specified date, only versions with a specified date are
applicable to this document. In terms of references without a specified date, the latest
version (including all the modifications) is applicable to this document.
GB/T 223.5 Steel and Iron - Determination of Acid-soluble Silicon and Total Silicon
Content - Reduced Molybdosilicate Spectrophotometric Method
GB/T 223.8 Methods for Chemical Analysis of Iron, Steel and Alloy - The Sodium
Fluoride Separation - EDTA Titration Method for the Determination of Aluminum
Content
GB/T 223.11 Iron, Steel and Alloy - Determination of Chromium Content - Visual
Titration or Potentiometric Titration Method
GB/T 223.14 Methods for Chemical Analysis of Iron, Steel and Alloy - The N-Benzoy-
N-Phenylhydroxylamine Extraction Photometric Method for the Determination of
Vanadium Content
GB/T 223.18 Methods for Chemical Analysis of Iron, Steel and Alloy - The Sodium
Thiosulfate Separation Iodimetric Method for the Determination of Copper Content
GB/T 223.23 Iron, Steel and Alloy - Determination of Nickel Content - The
Dimethylglyoxime Spectrophotometric Method
GB/T 223.25 Methods for Chemical Analysis of Iron, Steel and Alloy - The
Dimethylglyoxime Gravimetric Method for the Determination of Nickel Content
GB/T 223.26 Iron, Steel and Alloy - Determination of Molybdenum Content - The
Thiocyanate Spectrophotometric Method
GB/T 223.53 Methods for Chemical Analysis of Iron, Steel and Alloy - The Flame
Atomic Absorption Spectrophotometric Method for the Determination of Copper
Content
GB/T 223.58 Methods for Chemical Analysis of Iron, Steel and Alloy - The Sodium
Arsenite-sodium Nitrite Titrimetric Method for the Determination of Manganese Content
GB/T 223.59 Iron, Steel and Alloy - Determination of Phosphorous Content - Bismuth
Phosphomolybdate Blue Spectrophotometric Method and Antimony
Phosphomolybdate Blue Spectrophotometric Method
GB/T 223.69 Iron, Steel and Alloy - Determination of Carbon Contents - Gas-volumetric
Method after Combustion in the Pipe Furnace
GB/T 223.72 Iron, Steel and Alloy - Determination of Sulfur Content - Gravimetric
Method
GB/T 224 Determination of Depth of Decarburization of Steels
GB/T 230.1 Metallic Materials - Rockwell Hardness Test - Part 1: Test Method (scales
A, B, C, D, E, F, G, H, K, N, T)
GB/T 247 General Rule of Acceptance, Package, Mark and Certification for Steel
Plates (sheets) and Strips
GB/T 709-2019 Dimension, Shape, Weight and Tolerance for Hot-rolled Steel Strip,
Plate and Sheet
GB/T 2970-2016 Method for Ultrasonic Testing of Thicker Steel Plates
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric
Analysis of Carbon and Low-alloy Steel (routine method)
GB/T 6394 Determination of Estimating the Average Grain Size of Metal
GB/T 8170 Rules of Rounding off for Numerical Values & Expression and Judgement
of Limiting Values
GB/T 10561-2005 Steel - Determination of Content of Nonmetallic Inclusions -
Micrographic Method Using Standards Diagrams
GB/T 17505 Steel and Steel Products - General Technical Delivery Requirements
GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the
Determination of Chemical Composition
3 Terms and Definitions
The following terms and definitions are applicable to this document.
3.1 Pre-hardening
Pre-hardening means to make mould steel reach a specific hardness state through the
method of thermal treatment before the mould is manufactured.
4 Order Content
The contract or order form that orders in accordance with this Part shall include the
following content:
a) Serial No. of this Part;
b) Product name;
c) Designation (see 6.1);
d) Specification;
e) Weight (or quantity);
f) Dimension and shape accuracy;
g) Group of delivery hardness (see 6.4; when it is not indicated, it is Level-L);
h) Special requirements (see 6.8).
5 Dimension, Shape and Weight
5.1 The dimension, shape, weight and tolerance of steel plates shall comply with the
stipulations of GB/T 709-2019. The allowable deviation of thickness shall comply with
Type-C stipulations in GB/T 709-2019.