This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 4156-2007 Metallic materials - Sheet and strip - Erichsen cupping test, the following main technical changes have been made with respect to GB/T 4156-2007.
——The normative references are modified (see Clause 2 of this standard; Clause 2 of Edition 2007);
——The range of the sample width or diameter b in Table 1 are modified from 30≤b<55 to 30≤b≤55, which is consistent with the international standard (see Table 1, Table 1 of Edition 2007).
This standard uses the translation method equivalent to ISO 20482:2013 Metallic materials - Sheet and strip - Erichsen cupping test.
The Chinese documents consistent and corresponding with the normative international documents in this standard are as follows:
——GB/T 3505-2009, Geometrical product specifications (GPS) - Surface texture: Profile method - Terms definitions and surface texture parameters (ISO 4287:1997, IDT)
The following editorial changes have been made in this standard:
——The printing error of the position indicated by the down arrow of h1 in Figure 1 is Corrected (see Figure 1, Figure 1 of ISO 20482:2013);
——The "Note” is added, indicating that the use of different types of lubricants will affect the test results (see 9.2);
——The "Note” is added to provide the basis for stopping the movement of the punch (see 9.6).
This standard was proposed by China Iron and Steel Industry Association.
This standard is under the jurisdiction of SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous editions of the standard replaced by this standard are as follows:
——GB/T 4156-1984 and GB/T 4156-2007.
Metallic materials - Sheet and strip - Erichsen cupping test
1 Scope
This Standard specifies a standard test method for determining the ability of metallic sheets and strips.
This standard applies to the determination of thickness from 0.1 mm up to 2.0 mm and a width of 90 mm or greater to undergo plastic deformation in stretch forming. For materials that are thicker and when only narrower strips are available, tools of specified dimensions are provided, in which case subscripts are used, as shown in Table 1.
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 (including any amendments) applies.
ISO 4287, Geometrical product specifications (GPS) - Surface texture: Profile method - Terms, definitions and surface texture parameters
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
through crack
crack that goes through the full thickness of the test piece and is just sufficiently wide to allow light to pass through part of its length
4 Symbols and interpretations
Symbols and designations used in this Standard are illustrated by Figure 1 and given in Table 1
Figure 1 Schematic representation - Erichsen cupping index
Table 1 Symbols and interpretations Dimensions in millimeters
Symbol
Designation Test piece and tool dimensions, and Erichsen cupping indices
Standard test Tests with thicker or more narrow sheets
a Thickness of the test piece 0.1 ≤ a ≤ 2 2 < a ≤3 0.1 ≤ a ≤ 2 0.1 ≤ a ≤ 1
b Width or diameter of the test piece ≥ 90 ≥ 90 55≤b<90 30 ≤ b ≤55
d1 Diameter of the spherical end of the punch 20 ± 0.05 20±0.05 15±0.02 8±0.02
d2 Bore diameter of the die 27 ± 0.05 40±0.05 21±0.02 11±0.02
d3 Bore diameter of the blank holder 33 ± 0.1 33±0.1 18±0.1 10±0.1
d4 Outside diameter of the die 55 ± 0.1 70±0.1 55±0.1 55±0.1
d5 Outside diameter of the blank holder 55 ± 0.1 70±0.1 55±0.1 55±0.1
R1 Outside corner radius of the die, outside corner radius of the blank holder 0.75 ± 0.1 1.0±0.1 0.75±0.1 0.75±0.1
R2 Inside corner radius of the die 0.75 ± 0.05 2.0±0.05 0.75±0.05 0.75±0.05
h1 Height of the inside rounded part of the die 3.0 ± 0.1 6.0±0.1 3.0±0.1 3.0±0.1
h Depth of the indentation during the test — — — —
IEa Erichsen cupping index IE IE40 IE21 IE11
a The corresponding Erichsen cupping index is designated for the standard test. For thicker materials and narrower specimens of thinner materials, the & dimension is added to the index.
5 Principle
Forming an indentation by pressing a punch with a spherical end against a clamped test piece between a blank holder and a die until a through crack appears. The measured depth of the indentation is the result of the test based on the movement of the punch.
6 Testing equipment
6.1 The test shall be carried out on a machine equipped with a die, punch and blank holder with dimensions and tolerances as given Table 1.
6.2 The construction of the machine shall be such that it is possible to observe the outside of the test piece during the test in order to be able to determine the instant when a through crack appears.
Note: In general, the commencement of rupture is accompanied by a drop in the force sustained by the test piece and sometimes by perceptible noise.
6.3 The machine shall be equipped with a gauge for measuring the movement of the punch with a scale division of 0.1 mm.
6.4 The die, the blank holder and the punch shall be sufficiently rigid not to deform during the test. The Vickers hardness of working surfaces of the die, the blank holder and the punch shall be at least 750HV30. It shall meet the following requirements:
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and interpretations
5 Principle
6 Testing equipment
7 Test piece
8 Test conditions
9 Test procedures
10 Test report
Annex A (Informative) Recommended composition of the graphite grease
Bibliography
