Metallisches Strahlmittel
Gerundetes Stahldrahtkorn
Bezeichnung, Güteanforderungen, Prüfungen
Peening media, cut wire shots;
Nomenclature, quality requirements, tests
VDFI 8001
Edition May 2009
Superdes VDFI 8001
October 1994
1 PURPOSE
Peening media ud in the spring industry are generally ud to improve the durability of springs under dynamic stress.
The method applied – shot peening - is a manufacturing process who result directly depends on the kind of peening medium applied. Therefore, certain requirements which are defined in this standard must be met by the peening media.
2 APPLICABILITY
This standard applies to shot with the applicable dimensions of the cut wire shots being listed in table 2.
3 TERMS
Conditioned (rounded) Cut Wire Shot describes the state in which the peening medium is ud for shot peening. The degree of conditioning is more or less pronounced, depending on the application.
•The abbreviation for the peening medium “Cut wire Shots“ is StD.
•The abbreviation for the shape of grain “conditioned“ of the peening medium is G.
•The degree of conditioning of the cut wire shots is specified by the figures 1, 2 or 3.
4 DESIGNATION
The designation of a peening medium compris
a) the denomination,
b) the abbreviation for the type of peening medium,
c) the abbreviation for the shape of grain of the peening medium,
d) the grade of conditioning,
e) the nominal diameter of the cut wire shots in mm,
f) the nominal value of Vickers hardness specified by the suffix HV, and
g) the abbreviation for this standard.
The elements b) and c) as well as d) to g) are each parated by a hyphen.
Example:
belton
The designation for the peening medium “Cut wire shots“, conditioned in compliance with figure 1 a) in the standard ries 8.1, nominal diameter of the cut wire 0.8 mm, nominal Vickers hardness 640 HV1, is:
Metallic abrasive StD-G1-0.8-640HV-VDFI 8001
5 REQUIREMENTS
5.1 Material
The source material ud for the manufacture of cut wire shots is wire rod acc. to DIN EN 10016-2.
5.2 Steel wire
The prematerial usually ud for cut wire shot is patented cold-drawn steel wire acc. to DIN EN 10270-1. The relevant tensile strength must be t so that the hardness specified in table 2 is achiev
会计实操班ed. The prematerial must be newly manufactured steel wire, who surface must be without deep cracks, grooves or scale. The surface must be dry and free of oil and corrosion. Coatings ud for corrosion prevention such as cadmium, tin, zinc and paint are inadmissible, unless specified otherwi. Phosphate-coated steel wire may be ud.
5.3 Shape and dimensions of grain
5.3.1 Shape of grain
The three figures shown in ction 8.1 must be deemed a standard ries for the shape of grain and the degree of conditioning. Deviations from the examples prented are possible. The tolerance margin for deviation must be agreed upon between the supplier and the customer. The proportion of defective grain found acc. to ction 6.2.2 must not exceed 2‰*). If a proportion of defective grain between 2‰ and 4‰ is found during the first test, a cond test is allowed which, however, must then meet the 2‰ limit. A proportion of defective grain of more than 4‰ results in direct rejection.
5.3.2 Grain dimensions
接电话用英语怎么说
Grain dimensions of conditioned cut wire shot are found by a screening analysis acc. to ction 6.2.3. The screening analysis must result in the following screening residue:
• 1st screen: ≤5 % • 2nd screen: ≥85 %
• 3rd screen: ≤10 % • Percentage of dust: ≤ 0.5 %
5.4 Hardness
The arithmetic mean of Vickers hardness HV0.5 or HV1 found must be within the tolerance range as specified in table 2. The tolerance range of the individual Vickers hardness values is larger and can also be found in table 2.
5.5 Service life
The rvice life of the peening medium tested and found acc. to ction 6.2.5 is calculated by the number of cycles performed in the Ervin tester; it must at least reach the number of cycles specified in table 2.
6 TESTING
6.1 Sampling
The quantity of conditioned cut wire shot required for all tests is taken according to DIN EN ISO 11125-1 and divided into the standardid sample quantities required for the individual tests.
6.2 Test procedure
6.2.1 Determination of the carbon content
The carbon content is determined on the basis of the incineration method.
6.2.2 Determination of the shape of grain and proportion of defective grain
Cut wire shot taken from a subsample is distributed denly in a single layer on a level surface; an adhesive tape of 100 mm x 30 mm is ud to take a layer of cut wire shots, which is then subjected to a visual inspection.
The shape of grain is evaluated at x20 to x25 magnification by comparison with the standard ries shown in ction 8.1. The same magnification is ud to ascertain the proportion of defective grain.
A maximum quantity of defective grain of 2 ‰, e.g. wire shots not conditioned and grains of the neighbouring conditioning stage may be found on the test surface of 3,000 mm². If a defective propor
tion between 2 ‰ and 4 ‰ is found during the first test, a cond test is allowed which, however, must then meet the 2 ‰ limit.
*)
2 ‰ equivalent 2/1000
Depending on the nominal diameter of wire shots, the rate of 2 ‰ or 4 ‰ means the following in absolute figures:
Proportion of defective
grains in units Nominal diameter of
wire shots
in mm
at 2 ‰ at 4 ‰
0.2 25 50 0.3 21 42 0.4 18 36 0.6 14 28 0.7 11 22 0.8 8 16 0.9 6 12 1.0 5 10 1.2 4 8
Table 1: proportion of defective grain at 2 ‰ and 4 ‰, depending on the nominal diameter of wire shots
6.2.3 Screening analysis
The sample quantity required for the screening test is taken from a subsample of the cut wire shot. Screening is performed by means of a t of test screens. The amount of grain remaining on each screen must be weighed and recorded in the form of a percentage of the quantity of shot tested. The result of the manual screening is definitive.
The mesh size of the test screens is:
• 1st screen: mesh size = nominal diameter of cut wire shot + 0.1mm • 2nd screen: mesh size = nominal diameter of cut wire shot
• 3rd screen: mesh size = nominal diameter of cut wire shot – 0.1mm
6.2.4 Determination of hardness
A minimum of 50 grains are taken from a subsample of cut wire shots, distributed in a single layer an
d embedded into epoxy resin which cures at a temperature of <140 °C. The test piece must be wet-ground after curing and polished with a diamond powder who average grain size is 3 µm. Grinding and polishing of the surface must be continued down to one third of the nominal diameter of the relevant cut wire shots. The expod, polished surfaces of the grains are very lightly etched with 3 % alcoholic nitric acid.
A hardness measurement acc. to DIN EN ISO 6507 is performed at the centre of 20 grains who microstructure clearly indicates that they have been cut in longitudinal direction; then the arithmetic mean is calculated.
Test forces are as follows:
• for nominal diameters of cut wire shots of 0.2 mm and 0.3 mm: 4.9035 N (HV0.5) • for nominal diameters of cut wire shots of 0.4 mm to incl. 1.2 mm: 9.8070 N (HV1)
6.2.5 Service life tests
A quantity of 220 g is taken from a subsample of the cut wire shots. A portion of 100 g of that quantity is placed into the Ervin tester. One cycle is completed after 500 revolutions. After each cycle
the smaller particles are removed from the operating mix via a parating screen (mesh size: 0.3 mm *)) and the quantity lost is replaced with the same quantity of fresh grain. The operation of cycles is continued until the total loss exceed 100 g. The application of linear interpolation allows a deduction of the number of revolutions resulting in a total loss of 100 g. That number of revolutions is the rvice life.
*)
For the nominal diameter of cut wire shots of 0.3 mm, the parating screen has a mesh size of 0.2 mm. If the nominal diameter of cut wire shots is 0.2 mm, testing is impossible at prent.
6.2.6 Rejection
If requirements in ction 5 are not met, the relevant batch can be rejected. The manufacturer must be
informed about the intended rejection and given the opportunity of convincing himlf of the justification of
the complaint.
7 QUOTED STANDARDS
•DIN EN 10016-2 Non-alloy steel rod for drawing and/or cold rolling - Part 2: Specific
requirements for general purpo rodqs2021年世界大学排名
•DIN EN 10270-1 Steel wire for mechanical springs – Part 1: Patented cold drawn unalloyed
steel wiregoodending
•DIN EN ISO 11125-1 Preparation of steel substrates before application of paints and related
products - Test methods for metallic blast-cleaning abrasives – Part 1:
Sampling
•DIN EN ISO 6507 Metallic materials - Vickers hardness test
8 STANDARD SERIES AND QUALITY REQUIREMENTS
合伙人英文8.1 Standard ries shape of grain
theotherdaya) b) c)
G1 G2 G3 Fig. 1: Shape of grain:
a) Grade of rounding G1
b) Grade of rounding G2
c) Grade of rounding G3
8.2 Quality requirements for conditioned cut wire shots
Vickers hardness tests
Service life minimum number of revolutions during ERVIN test
蔬菜的英文
Cut wire shots - Nominal diameter
in mm
T e s t f o r c e
Nominal value
Limit values
of the mean value of 20 measured grains (± 30HV)
Limit values
of the
individual
values of the 20
measured
grains (± 60HV)
Type of material
acc. to DIN EN 10016-2
G1 G2 G3
dmcl640 610 - 670 580 - 700 C72D / C76D
670 640 – 700 610 - 730 C72D / C76D
0.2
700 670 - 730 640 - 760 C82D / C86D not testable 640 610 - 670 580 - 700 C72D / C76D 4,600 4,5004,400670 640 – 700 610 - 730 C72D / C76D 4,500 4,4004,3000.3
H V 0.5
700 670 - 730 640 - 760 C82D / C86D 4,600 4,5004,400640 610 - 670 580 - 700 C72D / C76D 4,400 4,3004,200670 640 – 700 610 - 730 C72D / C76D 4,300 4,2004,1000.4
700 670 - 730 640 - 760 C82D / C86D 4,400 4,3004,200640 610 - 670 580 - 700 C72D / C76D 4,200 4,1004,000670 640 – 700 610 - 730 C72D / C76D 4,100 4,0003,9000.5
700 670 - 730 640 - 760 C82D / C86D 4,200 4,1004,000640 610 - 670 580 - 700 C72D / C76D 4,000 3,9003,800670 640 – 700 610 - 730 C72D / C76D 3,900 3,8003,7000.6
700 670 - 730 640 - 760 C82D / C86D 4,000 3,9003,800640 610 - 670 580 - 700 C72D / C76D 3,700 3,6003,500670 640 – 700 610 - 730 C72D / C76D 3,600 3,5003,4000.7pretend是什么意思
700 670 - 730 640 - 760 C82D / C86D 3,700 3,6003,500640 610 - 670 580 - 700 C72D / C76D 3,500 3,4003,300670 640 – 700 610 - 730 C72D / C76D 3,400 3,3003,2000.8
700 670 - 730 640 - 760 C82D / C86D 3,500 3,4003,300640 610 - 670 580 - 700 C72D / C76D 3,300 3,2003,100670 640 – 700 610 - 730 C72D / C76D 3,200 3,1003,0000.9
700 670 - 730 640 - 760 C82D / C86D 3,300 3,2003,100640 610 - 670 580 - 700 C72D / C76D 3,100 3,0002,900670 640 – 700 610 - 730 C72D / C76D 3,000 2,9002,8001.0
700 670 - 730 640 - 760 C82D / C86D 3,100 3,0002,900640 610 - 670 580 - 700 C72D / C76D 3000 2900 2800 670 640 – 700 610 - 730 C72D / C76D 2900 2800 2700 1.2 H V 1
700
670 - 730 640 - 760 C82D / C86D 3000 2900 2800
Table 2: requirements of hardness and rvice life for cut wire shots
