This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of high carbon lead free-cutting steel bars. This standard is applicable to free-cutting steel bars used in the manufacture of watch parts and other precision mechanical parts. QB/T 2272-1996 Y100Pb high carbon lead free-cutting steel bars for watches QB/T2272-1996 Standard download decompression password: www.bzxz.net

QB/T2272—1996
This standard is revised from the original professional standard ZBY11021—1988 for Y100Pb high carbon temporary cutting rods. During the revision process, the main technical parameters of the original professional standard were retained, and some chapters and clauses were modified and supplemented to a large extent. The main differences between this standard and the original ZBY11021—1988 are as follows: -- The writing format and expression method are in accordance with GB/T1.1—1993 Guidelines for Standardization Work Unit 1: Draft and Expression Rules of Standards Part 1: Basic Regulations for Standard Writing\Implementation Rules
- A chapter on definitions is added and listed as Chapter 3 in the standard; -5.2 adds quality classification requirements for steel bars; -5.5 Table 4 Note changes the original tensile strength and elongation to Vickers hardness; -7.4 lists the inspection of the external dimensions and surface quality as inspection of each bar. This standard is proposed by the Quality Standards Department of China Light Industry General Association. This standard is under the jurisdiction of the National Clock and Watch Standardization Center. The drafting unit of this standard is Nanjing Clock and Watch Material Factory. The main drafters of this standard are Fei Xinghua, Shen Yufen, Xia Qiufang, Ji Huimin, and Ye Tinglan. From the date of implementation of this standard, the professional standard ZBY11021-1988 Y100Pb high carbon lead free-cutting steel bar for watch use issued by the former Ministry of Light Industry will be invalid.
1 Scope
Light Industry Industry Standard of the People's Republic of China
Y100Pb high carbon lead free-cutting steel bar for watch use
QB/T 22721996
This standard specifies the product classification, technical requirements, test methods, inspection rules, packaging, marking, transportation, and storage of high carbon lead free-cutting steel bars.
This standard applies to free-cutting steel bars used in the manufacture of watch parts and other precision machinery parts. 2 Reference standards
The clauses contained in the following standards constitute the clauses of this standard by being referenced in this standard. The versions shown are valid at the time of publication of this standard. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T223.4-1988 Chemical analysis methods for steel and alloys - Determination of manganese content by ammonium nitrate oxidation volumetric method GB/T 223.5—1988
Chemical analysis methods for steel and alloys - Determination of silicon content by oxalic acid-ferrous sulfate and molybdenum-silicon blue photometric method GB/T 223.29—1984
GB/T 223.61—1988
GB/T 223.68—1989
GB/T 223. 69—1989
Methods for chemical analysis of steel and alloysCarrier precipitation-dimethoxycarbonate spectrophotometric determination of lead contentMethods for chemical analysis of steel and alloysAmmonium phosphomolybdate volumetric method for determining phosphorus contentMethods for chemical analysis of steel and alloys:
Combustion-potassium iodate volumetric method for determination of sulfur content
Chemical analysis methods for steel and alloys
Determination of carbon content by combustion gas volumetric method
GB/T228—1987Methods for tensile testing of metals
GB/T 1958—1980
Rules for testing shape and position tolerances
GB/T 5030—1985
Metal test method for small load Vickers hardness
GB/T10610—1989Rules and methods for measuring surface roughness with stylus instrumentsY13/T 28—1959
Metal microstructure inspection method
3 Definitions
This standard adopts the following definitions.
3.1 Roundness: the difference between the maximum diameter and the minimum diameter measured on a cross section. 3.2 Cylindricity: the difference between the maximum diameter and the minimum diameter of the cross section at both ends of the roundness within a length of 1m. 4 Product classification
4.1 Product brand: Y100Pb
4.2 Basic steel dimensions: as specified in Table 1.
Basic dimensions
1 The specifications and dimensions in this table are selected from the R40 series of GB/T321. 2 Special specifications can be negotiated by the supply and demand parties. Approved by China Light Industry Association on 1997-0T-27
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Implementation on 1997-09-01
4.3 The surface of the steel bar is polished.
4.4 Marking example
QB/T 2272—1996
A grade A polished steel bar made of Y100Pb with a diameter of 1.20mm and a length of 2000mm is marked as: polished Y100PbA1.20×2000QB/T2272—1996
5 Technical requirements
The chemical composition of steel pieces shall comply with the provisions of Table 2.
Table 2 Chemical composition
YIUoPb
0. 95~1. 04
0. 35 ~0. 6§
0. 04 ~~0. 08
The quality of steel pieces is divided into two grades, A and B, according to the limit deviation of the diameter. The limit deviation of the diameter and length is shown in Table 3. Table 3 Limit deviation of diameter and length
Size range
>3. 0-~6. 0
Limit deviation
Basic size
Limit deviation
General: The short length of the fixed-length steel bar shall not be less than 1500m, and its weight shall not exceed 10% of the weight of each batch of delivery, and shall be packed in grades: 5.3
The roundness and cylindricity of the steel bar shall not be greater than half of the diameter plate limit deviation specified in Table 3. Copper bar: Surface roughness R, not greater than 0. 8 μm1. The mechanical properties of the steel bar shall comply with the provisions of Table 4.
Table 4 Mechanical properties
0. 81~1. 10
>1. 10~-3. 00
>3. 00~~ 4, 00
>4. 00~6. 00
Vickers hardness (HVI)
280~320
270~310
260~300
250~290
260~-3C0
250~290
240~280
Tensile stiffness ab, N/mm
≥930
730-~900
Note: Vickers hardness is the basis for assessment. For assessment of tensile strength and tensile strength, the hardness is not assessed. 5.6 Microstructure
5.6.1 The spheroidized pearlite structure shall conform to No. 2, 3, and 4.5 of the pearlite grade brush pattern in Figure 1. Fb
0. 15 ~0. 30
Basic size
2a1 500
Elongation.%
Note: Figure 1 is a sample of the first level 1 figure of the pearlite structure level 3 in GB/T1298-1986 (Technical conditions for carbon tool steel). 5.6-2 No decarburized layer is allowed on the surface.
5.6.3 No free graphite carbon is allowed.
5.6.4 The lead distribution should be fine and uniform.
5.7 The steel ladder should be straight without distortion, and the straightness per meter should not exceed 0.5mm. 5.8 The steel ladder is not allowed to have cracks, and the surface should be free of obvious defects such as wear marks. 8
6 Test method
6.1 Chemical composition analysis method
QB/T 2272-1996
6.1.1 Carbon content shall be in accordance with GB/T 223.69. 6.1.2 Silicon content shall be in accordance with GB/T 223.5. 6.1.3 Manganese content shall be in accordance with GB/T 223.4. 6.1.4 Sulfur content shall be in accordance with GB/T 223.68. 6.1.5 Phosphorus content shall be in accordance with GB/T 223.61. 6.1.6 Lead content shall be in accordance with GB/T 223.29. 6.2 Grain elongation test and hardness test shall be in accordance with GB/T 228 and GB/T 5030 respectively. 6.3 Microscopic inspection shall be in accordance with YB/T 28. 6.4 Length shall be measured with a tape measure, diameter, reading and cylindricity shall be measured with an outside micrometer with a graduation value of 0.001 mm at a distance of 40 mm from both ends of the steel bar. Measure the area within.
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Figure No. 1
Figure No. 3
Figure No. 5
QB/T 2272-1996
Figure 1 Pearlite Grade Diagram
Figure No. 2
Figure No. 4
Figure No. 6
QB/T 2272—1996
6.5 Straightness inspection: When the steel bar is ground on the platform, it should feel no obvious jump: If necessary, follow the straightness error detection scheme 1-1 in Appendix 1 of GB/T195.
6.6 The appearance quality and surface roughness shall be visually inspected with normal vision. If necessary, the surface roughness shall be carried out in accordance with the provisions of GB/T, 10610.The R value can also be measured with a light-section microscope and then converted to the R value. 7 Inspection rules
Steel bars shall be inspected by the supplier's quality inspection department and the product quality shall be guaranteed to meet the requirements of this standard. The buyer's acceptance period shall be within 60 days after the delivery
7.2 Steel bars shall be grouped in batches of the same grade, same specification and grade, and each batch shall not exceed 300kg. 7.3 Chemical composition, tensile test and hardness test shall be tested by taking two samples from each batch for preparation. The lower limit of carbon content in the chemical composition of 5% of the batch during acceptance is allowed to be 0.93%.
7.4 Steel bars shall be measured for external dimensions, appearance quality and surface roughness inspection one by one. 7.5 Re-test bzxZ.net
Even if the test result of each test sample is unqualified, double samples shall be drawn from the batch for re-testing of the unqualified items. If one sample is still unqualified in the re-testing result, the whole batch shall be scrapped or inspected one by one. The qualified ones shall be accepted in a separate batch. 8 Packaging, marking, transportation, storage
8.1 Packaging
Steel bars should be coated with anti-rust oil and packed with anti-rust paper, anti-paste paper, plastic bags, etc. Each bundle of 10-20kg of the same specification should be packed in a packaging box lined with moisture-proof paper.
The anti-rust period of steel bars after packaging is six months. 8.2 Marking
B.2.1 Each box of steel bars should be hung with a label, which should be clear, firm and reliable, and marked with a) manufacturer's name and trademark;
b) product name;
c) batch number, weight, and specifications.
8.2.2 Each batch of steel bars should have a quality guarantee, which should indicate: a) manufacturer name and trademark; h) product name, specification, status; d) product standard number and product mark; e) production date and batch number; f) various test results and inspection marks.
8. 3 Transportation, this storage should be prevented from being damaged, soaked, damp and corroded by chemical gases during transportation and storage, and the original packaging should be kept intact. 428
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