National Standard of Tungsten Carbide Powder
GB/T 4295——2008
instead of GB/T 4295——1993
Tungsten Carbide Powder
2008-03-31publish 2008-09-01 imlement
1 Range
The standard stipulates the requirement, testing method, testing rules, mark, packing, transport, storage and PO or contract form of tungsten carbide powder.
This method is applied to tungsten carbide powder which is used to manufacture tungsten carbide product.
2 Normatively reference document
The following terms being referred has become the terms of this standard. The standard noted with date which may be adjusted thereafter does not apply to this standard. However, both parties can discuss whether to adopt these modified standards or not. Referred documents without date can be applied to this standard if there is any modification.
GB/T 3249 Testing method for refractory metal or powder compound: Fsss Method.
GB/T 4324 Chemical analyse method of tungsten
GB/T 5124 Analyse method of tungsten carbide
GB/T 5314 Testing for specific surface area of powder metallurgy:Nitrogen adsorption
3 Requirement
3.1 Product catagory
Tungsten carbide powder can be divided into 16 grades according to its average partical size distribution, below is expressing method:
Example：FWC 100-140
FWC：Tungsten carbide powder；100-140 means average particle distribution range is 10.0µm~14.00µm
3.2 Chemical component
The chemical component should conform with the stipulation of Table 1.
Table 1
Content |
Impurities Content (No Less Than) |
||||||||
Al |
Ca |
Fe* |
K |
Mg |
Mo |
Na |
S |
Si |
|
≥99.8 |
0.002 |
0.002 |
0.02 |
0.0015 |
0.002 |
0.01 |
0.0015 |
0.002 |
0.003 |
*For average particle size which is bigger than 14um, the requirement for Fe should be less than 0.05%. |
|||||||||
Its Fsss size, specific surface area, total carbon, free carbon, chemical carbon and oxygen content should conform with stipulation of Table 2.
3.4 Sieving Tungsten carbide powder should be sieved. For the powders which grain size is less than 2um, its mesh size should no bigger than 150um; for Fsss size 2um~10um, its mesh size should no bigger than 75um; for Fsss size bigger than 10um, the mesh size should be less than 180um.
Grade |
Specific Surface Area/(m2/g) |
Average Particle Range |
Oxygen Content |
Total Carbon/ |
Free Carbon |
Chemical Carbon |
FWC02-04 |
＞ |
-- |
0.35 |
6.20~6.30 |
0.20 |
6.07 |
FWC04-06 |
1.5~2.5 |
-- |
0.30 |
6.15~6.25 |
0.15 |
6.07 |
FWC06-08 |
-- |
≥0.60~0.80 |
0.20 |
6.13~6.23 |
0.12 |
6.07 |
FWC08-10 |
-- |
＞0.8~1.00 |
0.18 |
6.08~6.18 |
0.08 |
6.07 |
FWC10-14 |
-- |
＞1.00~1.40 |
0.15 |
6.08~6.18 |
0.06 |
6.07 |
FWC14-18 |
-- |
＞1.40~1.80 |
0.15 |
6.08~6.18 |
0.06 |
6.07 |
FWC18-24 |
-- |
＞1.80~2.40 |
0.12 |
6.08~6.18 |
0.06 |
6.07 |
FWC24-30 |
-- |
＞2.40~3.00 |
0.10 |
6.08~6.18 |
0.06 |
6.07 |
FWC30-40 |
-- |
＞3.00~4.00 |
0.08 |
6.08~6.18 |
0.06 |
6.07 |
FWC40-50 |
-- |
＞4.00~5.00 |
0.08 |
6.08~6.18 |
0.06 |
6.07 |
FWC50-70 |
-- |
＞5.00~7.00 |
0.05 |
6.08~6.18 |
0.06 |
6.07 |
FWC70-100 |
-- |
＞7.00~10.00 |
0.05 |
6.08~6.18 |
0.06 |
6.07 |
FWC100-140 |
-- |
＞10.00~14.00 |
0.05 |
6.08~6.18 |
0.06 |
6.07 |
FWC140-200 |
-- |
＞14.00~20.00 |
0.05 |
6.08~6.18 |
0.06 |
6.07 |
FWC200-260 |
-- |
＞20.00~26.00 |
0.05 |
6.08~6.18 |
0.06 |
6.07 |
FWC260-350 |
-- |
＞26.00~35.00 |
0.08 |
6.08~6.18 |
0.06 |
6.07 |
The appearance of tungsten carbide powder is grey and it turns dark with the increase of grain size. The color should be uniform and no visual inclusions.
4 Testing Method
4.1 The main content is calculated by subtraction of impurity content, its analyse method is according to GB/T 4324.
4.2 Total carbon, free carbon content follows GB/T 5124. Chemical carbon is calculated by subtraction of T/C and F/C. Oxygen content follows GB/T 3249. Tungsten carbide powder specific surface area follows GB/T 13390.
4.3 Seiving of the product is determined by both party.
4.4 Appearance is checked by visual method.
5 Testing rules
5.1 Inspection and acceptance
5.1.1 Product is tested by quality assurance department of supplier to insure the product is complied to the standard, the product quality certificate needed to be completed.
5.1.2 Demander can inspect the product according to this standard, if the testing result is differ from the standard, then supplier should bring it up within one month to the seller and negotiated by both party.If arbitration is needed, sampling should be taken by both party.
5.2 Lot grouping
Product should be examined by batch. Every lot is composited by the tungsten carbide powder of same grade, quantity is negotiated by both party.
5.3 Inspection item and sampling amount
Please check Table 3 for inspection item and sampling amount.
Inspection Item |
Sampling Amount |
Required Chapter Article |
Testing Method Chapter Article |
Chemical Components |
Every Batch Follows GB/T 5314 |
3.2 |
4.1 |
Grain Size, Specific Surface Area and Oxygen Content |
Every Batch Follows GB/T 5314 |
3.3 |
4.2 |
Sieving |
Lot for Lot |
3.4 |
4.3 |
Appearance Quality |
Lot for Lot |
3.5 |
4.4 |
5.4.1 If there is one item of the product is disqualification, then double amount of sample needs to be tested. If it is still disqualification, then this batch is unqualified.
5.4.2 If one of the grain size, specific surface area, total carbon, free carbon, chemical carbon and oxygen content of the product is unqualified, then double amount of sample needs to be tested. If it is still disqualification, then this batch is unqualified.
5.4.3 If the sieving is unqualified, so is this batch.
5.4.4 If the appearance quality is unqualified, so is this batch.
If you have any interest in tungsten carbide powder, please feel free to contact us by email: sales@chinatungsten.com or by telephone: +86 592 5129696.
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