JB/T 6958-1993 General technical conditions for precision blanking parts
Some standard content:
Machinery Industry Standards of the People's Republic of China
Precision blanking parts
1 Subject content and scope of application
General technical conditions
JB/T6958--- 93||tt| |This standard specifies the technical requirements, test methods, inspection rules, marking, packaging and transportation of precision blanking (hereinafter referred to as fine blanking) parts. This standard applies to metal fine-blanking parts produced by strong blanking methods. 2 Reference standards
GB223
GB 228
GB 930
GB231
GB 1031
GB1800
GB 2828| |tt||GB 2829
JB 3814
Methods for chemical analysis of steel and alloys
Metal tensile test method
Metal Rockwell hardness test method
Metal Brinell Hardness Test Method
Surface roughness parameters and their values
General Tolerances and Fits Standard Tolerances and Basic Deviations Batch-by-Batch Inspection Counting Sampling Procedures and Sampling Tables (Applicable to Continuous Batch Inspections ) Periodic inspection and counting sampling procedures and sampling tables (suitable for inspection of production process stability) Normalizing and annealing treatment of steel
JB/Z272
Structure manufacturability of precision blanking parts||tt| |JB/Z280 precision blanking parts quality
YB28 metal microstructure inspection method
3 technical requirements
3.1 ordering conditions
3.1.1 stipulate the required fine blanking Quantity and material of parts 3.1.2 The purchaser should provide part drawings and fine blanking parts drawings. If the party needs to provide part drawings, the supplier can draw fine blanking part drawings approved by both parties in accordance with the provisions of J13/1272.
3.1.3 Specifies the inspection scope, quality level and subsequent processing procedures of fine blanking parts. 3.2 Raw materials
3.2.1 The materials used for fine blanking parts should comply with the relevant standards, and the materials used for fine blanking parts should have quality certificates. 3.2.2 The fine-blanking parts manufacturer shall re-inspect some or all inspection items of the material according to relevant standards and quality certificates as needed. After passing the re-inspection, it will be put into production
3.2.3 When the surface condition of the material cannot meet the requirements of the fine blanking pattern, if there is an oxide layer, dirt or other defects on the surface of the material, complementary process measures should be used to Tool removal
3.2.4 For stainless steel, carbon steel and alloy steel, the carbide spheroidization rate should be above 90% and the tool should be evenly distributed. 3.2.5 When the metallographic structure of medium, high carbon steel and alloy steel does not meet the requirements of Article 3.2.4, spheroidizing annealing treatment is generally required before fine blanking. The spheroidizing annealing process is carried out in accordance with the provisions of JB3814. 3.2.6 The fine blanking performance of steel can be seen in Figure A1 in Appendix A (Reference Parts). Commonly used material grades for fine blanking parts can be found in the table in Appendix A. The Ministry of Machinery Industry of the People's Republic of China approved the implementation on 1994-07-01 on 1993-07-01
18
Al.
3.3 Quality of fine-blanking parts
JB/T6958-93
The quality of fine-blanking parts should comply with the requirements of the fine-blanking parts drawing and ordering contract. When the fine blanking part drawing is not marked and the ordering contract does not require it, the provisions of Articles 3.3.1 to 3.3.3 shall apply. 3.3.1 The dimensional tolerance should reach the IT12 level in GB1800, the sag angle should comply with the provisions of JB/Z280, the surface integrity rate of the shearing surface should reach the V level in JB/Z280, and the allowable tearing level of the shearing surface It should reach level 4 in JB/7.280, and the shear surface roughness should reach R2.5 in GB1031.
3.3.2 The verticality of the shearing surface shall be in accordance with the requirements of curve 1 in Figure B1 in Appendix B (reference part). The flatness of the non-shearing surface shall be in accordance with the requirements of curve B23 in Figure B2 of Appendix 1.
3.3.3 Non-front surface defects shall be determined in accordance with the relevant standards of the materials used. 4 Test methods
4.1 Chemical composition analysis, steel shall be carried out according to the provisions of GB223, and other materials shall be carried out according to the corresponding American standards. 4.2 The microscopic weaving inspection of steel shall be carried out in accordance with the provisions of YB28. 4.3 The tensile test shall be carried out in accordance with the provisions of GB228. 4.4 The hardness test shall be carried out in accordance with the provisions of B230 or GB231. 4.5 The roughness of the shearing surface shall be in accordance with the provisions of JB/Z280. 4.6 The identification of cracks and scars shall be carried out by visual inspection, coloring flaw detection and other methods. 4.7 Appearance inspection adopts hand feel, visual inspection, light reflection and other measurements. Dimensions, dimensional tolerances, geometric tolerances, etc. are measured using inspection tools or measuring instruments.
5 Inspection Rules
5.1 The inspection of fine blanking parts is divided into general inspection and supplementary inspection. 5.1.1... General inspection: dimensional tolerance, shear surface integrity level, shear surface allowable tearing level, shear surface verticality, sag, hair shaving, non-shear surface flatness, non-shear surface Surface quality, etc. 5.1.2 Supplementary inspection: shear surface roughness, flaw detection, chemical composition, mechanical properties, metallographic structure, etc. The types of such inspections are determined by negotiation between the supplier and the buyer.
5.2 Inspection of mental parts can be carried out random inspection or full inspection as needed. If random inspection is adopted, it shall be carried out in accordance with the regulations of GB2828 and GB2829. 5.3 For the inspection of certain items of fine-blanking parts, the fine-blanking samples approved by both parties can be used as the basis for comparison and judgment: such as the inspection of the shear surface yield grade and the shear surface allowable tear grade. Such inspection items are determined by negotiation between the supply and demand parties. 5.4 The inspection of finished fine blanking parts shall be carried out by the supplier's quality inspection department in accordance with the fine blanking part drawings, order contracts, this standard and the provisions of JB/Z280.
5.5 Acceptance of finished fine-blanking parts The quality inspection department of the purchaser shall conduct 5.6 fine-blanking parts inspection according to the quality certificate, fine-blanking part drawings, order compliance, this standard and JB/7.280 according to the provisions of GB2828.GB2829 The determination of batch grouping, sampling and inspection results shall be determined by negotiation between the supply and demand parties at the time of ordering. 6 Marking, packaging and transportation
6.1 Fine-blanking parts are generally not marked. When marking is required, it should be noted in the fine-blanking part drawing: 6.2 Each batch of fine-blanking parts should be supplied with a quality certificate. Its main contents are: a. Name of supplier;
ordering contract number, name of fine-blanking parts and part number of fine-blanking parts; h.
quantity of fine-blanking parts;
d, Material grade:
c． Inspection results for special requirements;
", the seal of the quality inspection department, the signature of the inspector and the date. 6.3 The rust prevention, packaging and transportation methods of fine-blanking parts should be stipulated in the order contract. 18|| tt||JB/T 6958
93
Appendix A
Fine blanking properties of steel and commonly used materials for fine blanking parts (reference parts)
For A1 fine blanking parts The fine blanking performance of steel is shown in Figure A1. The upper curve in Figure A1 is the fine blanking limit of steel. For dry fine blanking parts that are easy to fine blank (simple shape) and allow slight cracks on the shear surface, when the carbide spheroidization rate is This limit can be reached when it is more than 90% and evenly distributed. The carbon content of non-alloy steel or the equivalent carbon content of low-alloy steel is St-0. 25, Mn: 0. 60+Cr+Ni. .C=C+
A
20
4
80or
700
600
500||tt| |too
300
0. 2
. 4
Picture Al
r
0. 6
mmm
0. 8
1.0
1.2
Steel suitable for dry fine blanking
Ma+w
3
1.4 (when base, %
(A)
A2 fine blanking parts commonly used materials are listed in Table A1. For fine blanking performance of materials not listed, please refer to materials with similar chemical composition in Table A1 Come to judge.
Table A
Material
Steel
Material
Common materials for fine blanking parts
08 ,10,15,20,25,30,35,40,45,50,55.60,65,7016Mn,15CrMn.20CrMn,20CrMo
65Mn
T8A,T10A
0Cri3 .1Cr13.2Cr13.3cr13.4Cr13, 1Cr18Ni9T2, T3.T4
Copper and copper alloys
Aluminum and aluminum alloys
H62.H68, H80.H90.H96||tt| |HSn62-1.HNi65-3
QSn1-3,QA17.QBe1.7,QBc2
LL-LLe
LF2.F21
I.Y11.1.Y12
No.
187
JB/T6958--93
Appendix B
Perpendicularity and accuracy of shear surface of fine blanking parts Flatness of punched parts (reference parts) Www.bzxZ.net
The shear plane verticality tolerance that B1 fine blanking can achieve is shown in Figure B1, 0.0
0.04
0.00
9|| tt | The flatness tolerance of the piece within the range of 100mm |0.07
0.06
0.05
0. 04
0.03
0.02
0.014
3||tt| |9
10 11
12
1314
Fine blanking thickness t (mm)
Flatness tolerance of fine blanking parts
Figure B2
Additional Notes:
This standard is proposed and managed by the Beijing Institute of Mechanical and Electrical Engineering of the Ministry of Machinery Industry. The drafter of this standard is Niu Jinwang. tt||188
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