GB/T 35840.2-2018Steels for plastic mould—Part 2: Pre-hardening steel bars (English PDF)

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 & 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.

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

8 Inspection rules

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.

9 Packaging, marking and quality certificate

The packaging, marking and quality certificate of steel products shall comply with the provisions of GB/T 2101. […]