GB/T 38977-2020 English PDF (GBT38977-2020)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 38977-2020
Historical versions: GB/T 38977-2020
Preview True-PDF (Reload/Scroll if blank)

GB/T 38977-2020: Nanometer grain cemented carbide rod
GB/T 38977-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.160
H 72
Nanometer Grain Cemented Carbide Rod
ISSUED ON: JULY 21, 2020
IMPLEMENTED ON: JUNE 1, 2021
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 Classification, Model Representation Rules and Schematic Diagram of Rods
... 4 
4 Technical Requirements ... 5 
5 Test Methods ... 9 
6 Inspection Rules ... 10 
7 Marking, Packaging, Transportation, Storage and Quality Certificate ... 11 
8 Order Sheet (or contract) Content ... 12 
Nanometer Grain Cemented Carbide Rod
1 Scope
This Standard specifies the classification, technical requirements, test methods,
inspection rules, marking, packaging, transportation, storage, quality certificate and
order sheet (or contract) content of nanometer grain cemented carbide rod.
This Standard is applicable to nanometer grain cemented carbide rod, in which, the
average grain size of wolfram carbide (WC) in cemented carbide is not greater than
200 nm (hereinafter referred to as “rod”).
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 5242 Inspection Rules and Test Methods of Cemented Carbide Products
GB/T 5243 Marking, Packing, Transport and Storage of Cemented Carbide Products
3 Classification, Model Representation Rules and
Schematic Diagram of Rods
3.1 Classification
In accordance with the dimensional accuracy, the rods are divided into two categories:
rough rod products and finished rod products.
3.2 Model Representation Rules
3.2.1 Rough rod products
The representation of rough rod products is composed of four parts: rod blank code
(B), diameter value (D), length value (L) and additional information code, as it is shown
in the example.
Example:
accordance with the method determined by the demand-side and the supply-side
through negotiation.
5.2 The dimensions, allowable deviations and shape tolerances of the rods shall be
tested through measuring tools of corresponding precisions.
5.3 The metallographic structure and mechanical properties of the rods shall be
inspected in accordance with the stipulations of GB/T 5242, or shall be determined by
the demand-side and the supply-side through negotiation.
5.4 The appearance quality of the rods shall be inspected through visual inspection or
measuring tools of corresponding precisions. The surface roughness shall be
inspected through roughness standard block comparison method or roughness meter.
6 Inspection Rules
6.1 Examination and Inspection Acceptance
6.1.1 The products shall be inspected by the supply-side, which shall ensure that the
products comply with the stipulations of this Standard and the order sheet (or contract).
In addition, the product quality certificate shall be filled out.
6.1.2 The demand-side may inspect the received products in accordance with the
stipulations of this Standard. When the inspection result does not conform to this
Standard and the order sheet (or contract), it shall be submitted to the supply-side
within 3 months from the date of receipt of the products, and resolved between the
demand-side and the supply-side through negotiation. If arbitration is required, the
arbitration sampling shall be jointly carried out by the demand-side and the supply-side
on the demand-side’s site.
6.2 Batch
The products shall be submitted for inspection in batches. Each batch shall be
composed of products of the same chemical composition, the same specification and
the same category.
6.3 Inspection Items and Sampling
The inspection items and sampling of each batch of products shall comply with the
stipulations of Table 11.
6.4 Determination of Inspection Results
6.4.1 When the inspection results of the dimensions, allowable deviations and shape
tolerances of the product are disqualified, then, the product shall be determined as
disqualified.
6.4.2 When the inspection results of the metallographic structures and mechanical
properties of the products are disqualified, it is allowed to take another double size of
specimens for a repeated test on the disqualified items. If there is still disqualification
in the results of the repeated test, then, the batch of products shall be determined as
disqualified.
6.4.3 When the inspection result of the appearance quality of the product is disqualified,
then, the product shall be determined as disqualified.
7 Marking, Packaging, Transportation, Storage and
Quality Certificate
7.1 Marking, Packaging, Transportation and Storage
The marking, packaging, transportation and storage of the products shall comply with
the stipulations of GB/T 5243.
7.2 Quality Certificate
Each batch of products shall provide a product quality certificate, which shall indicate:
a) Supply-side’s name and address;
b) Product name;
c) Product category;
d) Product batch No.;
e) Net weight or quantity;
f) Various inspection results and technical supervision department’s imprint;
g) Date of inspection;
h) Serial No. of this Standard.