JB/T 9129-2000 JB/T 9129-2000 Metallographic inspection of 60SiMn steel cylindrical helical springs JB/T9129-2000 Standard download decompression password: www.bzxz.net

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Machinery Industry Standard of the People's Republic of China
JB/T 9129--2000
60Si2Mn Steel Helical Springs
Metallographic Test
60Si2Mn Steel Helical Springs Metallographic Test2000-04-24 Issued
National Bureau of Machinery Industry
2000-10-01 Implementation
JB/T 9129—2000
This standard is an editorial revision of the original ZBJ26001—R8 "60Si2Mn Steel Helical Springs", and the main technical content has not changed. This standard is proposed and managed by the National Technical Committee for Standardization of Springs. The drafting units of this standard are: Machinery City Science Research Institute, Shanghai Materials Research Institute. Revision of metallographic test. When revising, the original standard shall be revised. 1 Scope
Standard of the Machinery Industry of the People's Republic of China
60Si2Mn Steel Helical Spring Metallographic Test
baSizMn steel helical springs metalographic test JB/T 9129—2000
This standard specifies the metallographic test method and microstructure rating diagram of 60S2Mn steel helical spring after annealing and medium-temperature tempering. This standard is applicable to the microstructure evaluation of 60Si2Mn steel helical spring after annealing and medium-temperature tempering. Other Si-Mn steel and Mn steel helical springs can also be implemented as a reference.
2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T224-1987 Method for determining the depth of decarburization of steel 3 Preparation of specimens
During the process of cutting and preparing metallographic specimens, the paper texture should be prevented from changing. The surface of the polished specimen should be smooth and free of obvious scratches.
4 Microstructure inspection
4. 1 The specimen is etched with 2%~5% nitric acid alcohol solution. 4.2 The magnification during inspection is 500 times.
4.3 During inspection, the entire inspected surface should be observed first, and then the rating should be selected according to its representative field of view. The evaluation position of the microstructure of the spiral spring with a diameter greater than 20mm of steel shall be negotiated by the supply and demand parties. 4.4 The inspection of the decarburized layer shall comply with the provisions of GB/T224. 4.5 The inspection results shall be expressed in grades.
5 Inspection items and rating range
5.1 Quenching organization grade and evaluation are only for inspection between processes and are not accepted by both parties.) 5.1.1 The quality of heat treatment of spiral springs should be inspected in the quenched state. 5.1.2 According to the microstructure of different quenching temperatures and its influence on mechanical properties, the quenched organization is divided into five levels. See Table 1 and Figure 1.
Approved by the State Machinery Industry Corporation on April 24, 2000, implemented on October 1, 2000
Figure 11 Grade
JB/T 9129—2000
Table 1 Description of braided structure grades
Fine martensite, needle length 15μm
Fine martensite, needle length 20μm
Coarse martensite, needle length minus 35μm
Coarse martensite, needle length>53μm
Fine martensite and less massive iron ore
Rating diagram of braided structure
Figure 33
(500×)
Figure 22 Grade
Figure 44 Grade
5. [. 31~3 is qualified, 4~5 is qualified 5.2 Medium temperature tempering organization level and evaluation
JB/T 91292000
Figure 5 level
5.2.1 The organization of the finished product after rate tempering shall be evaluated according to this level chart. 5.2.2 The tempering organization is divided into five levels, see Table 2 and Figures 6 to 10. 5.2.31~3 levels are qualified, 4~5 levels are unqualified. Medium temperature tempering organization rating chart
Figure 61 level
(500×)
Figure 72 level
Figure 83 level
JB/T 9129—2000
Table 2 Medium temperature tempering organization level description
Fine tempered truncate
Relatively fine tempered truncate
Relatively coarse tempered tonite
Large tempered truncate
Tempered truncate and a small amount of massive truncate
Figure 105 level
Figure 94 level
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