GB/T 35840.2-2018 English PDF (GBT35840.2-2018)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 35840.2-2018
Historical versions: GB/T 35840.2-2018
Preview True-PDF (Reload/Scroll if blank)

GB/T 35840.2-2018: Steels for plastic mould -- Part 2: Pre-hardening steel bars
GB/T 35840.2-2018
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.35
H 40
GB/T 35840.2-2018
Steels for plastic mould - Part 2: Pre-hardening steel bars
ISSUED ON: MAY 14, 2018
IMPLEMENTED ON: FEBRUARY 01, 2019
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 Ordering contents ... 7
5 Dimensions, shape, weight and allowable deviation ... 7
6 Technical requirements ... 9
7 Test methods ... 12
8 Inspection rules ... 13
9 Packaging, marking and quality certificate ... 14
Annex A (normative) Standard diagrams for macrostructure of remelted steel bars and
billets ... 15
Steels for plastic mould - Part 2: Pre-hardening steel bars
1 Scope
This Part of GB/T 35840 specifies the terms and definitions, ordering contents,
dimensions, shapes, technical requirements, test methods, inspection rules, packaging,
marking and quality certificates of pre-hardening steel bars for plastic mould.
This Part applies to pre-hardening round steel, square steel and flat steel (hereinafter
referred to as steel) delivered by hot rolling, forging and machining for the manufacture
of plastic mould.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyryl
methane phosphomolybdate gravimetric method for the determination of
phosphorus content
GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon
content - Reduced molybdosilicate spectrophotometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual
titration or potentiometric titration method
GB/T 223.13 Methods for chemical analysis of iron, steel and alloy - The ammonium
ferrous sulfate titration method for the determination of vanadium content
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 223.19 Methods for chemical analysis of iron, steel and alloy - The
neocuproine-chloroform extraction photometric 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 223.72 Iron, steel and alloy - Determination of sulfur content - Gravimetric
method
GB/T 223.76 Methods for chemical analysis of iron, steel and alloy - The flame
atomic absorption spectrometric method for the determination of vanadium content
GB/T 223.82 Steel and iron - Determination of hydrogen content - Thermal
conductivity/infrared method after fusion under inert gas
GB/T 226 Test method for macrostructure and defect of steel by etching
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 908-2008 Forged bars - Dimensions, shape, weight and tolerances
GB/T 1299-2014 Tool and mould steels
GB/T 2101 General requirement of acceptance, packaging, marking and certification
for section steel
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents -
Spark discharge atomic emission spectrometric method (routine method)
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 6402-2008 Steel forgings - Method for ultrasonic testing
GB/T 8170 Rules of rounding off for numerical values and expression and judgement
of limiting values
GB/T 10561-2005 Steel - Determination of content of non-metallic 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
For the purpose of this document, the following terms and definitions apply.
3.1
pre-hardening
Through heat treatment, the mould steel reaches a specific hardness state before mould
manufacturing.
4 Ordering contents
The contract or order for steel products ordered in accordance with this Part shall
include the following contents:
a) serial number of this Part;
b) product name;
c) designation (see 6.1);
d) smelting method (see 6.2);
e) product specification dimensions, shape and allowable deviation group (see
Clause 5);
f) delivery status (see 6.3);
g) mass (or quantity);
h) special requirements;
5 Dimensions, shape, weight and allowable deviation
5.1 Hot-rolled steel bars
5.1.1 The dimensions, shape and allowable deviation of hot-rolled round steel and
square steel shall comply with the provisions of 5.1.1 of GB/T 1299-2014.
5.1.2 The dimensions, shape and allowable deviation of hot-rolled flat steel shall
comply with the provisions of 5.1.2 of GB/T 1299-2014.
5.2 Forged steel bars
5.2.1 Forged round and square steel
The dimensions, shape and allowable deviation of forged round and square steel shall
comply with the provisions of 5.2.1 of GB/T 1299-2014.
5.2.2 Forged flat steel
5.2.2.1 The dimensions and allowable deviation of forged flat steel with a nominal
width of 40 mm ~ 300 mm shall comply with the provisions of Group 2 in Table 4 of
Steel shall be checked and accepted in batches. Each batch of vacuum refined steel shall
consist of steel products of the same designation, same furnace number, same delivery
status, same specification and same heat treatment furnace. Each batch of electroslag
steel shall consist of steel products of the same designation, same electroslag furnace
number, same delivery status, same specification and same heat treatment furnace.
Under the conditions that the process is stable and the requirements of this Part can be
met, it shall take 1 sample from each electroslag furnace number for the chemical
composition of electroslag steel.
8.3 Sampling quantity and sampling location
The sampling quantity and sampling location for the inspection of steel products shall
comply with the provisions of Table 6.
8.4 Re-inspection and judgment rules
8.4.1 The re-inspection and judgment rules of steel products shall comply with the
provisions of GB/T 17505.
8.4.2 If the supply party can ensure that the steel products are qualified, for the
macrostructure and non-metallic inclusions of steel products or billets of the same
furnace number, it is allowed to replace small with large, replace product with billet,
and replace macrostructure with flaw detection.
8.4.3 The various inspection and check measurement values of steel products shall be
rounded off according to the rounding off value comparison method, and the rounding
off rules shall comply with the provisions of GB/T 8170.
9 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel products shall comply with the
provisions of GB/T 2101.