JB/T 9205-1999 Metallographic examination of pearlite ductile iron parts after induction hardening

JB/T 9205-1999 JB/T 9205-1999 Metallographic examination of pearlite ductile iron parts by induction hardening JB/T9205-1999 Standard download decompression password: www.bzxz.net

[CS 25. 200
Machinery Industry Standard of the People's Republic of ChinawwW.bzxz.Net
JB/T9205-1999
Pearlite spheroidal graphite cast iron parts
Metallographic examination of induction hardenedpearlitic spheroidal graphite cast iron parts1999-06-24 Issued
State Bureau of Machinery Industry
2000-01-01 Implementation
JE/T9205—1999
This standard is an editorial revision of the provisions of induction hardened pearlite spheroidal graphite cast iron parts in ZBJ3601088, and the main technical content has not changed. This standard replaces 2B J36 01088 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Heat Treatment Standardization. The drafting unit of this standard: Dongfeng Motor Corporation Technology Research Institute. The main drafters of this standard are Wan Guangyou and Zhang Ping. This standard was first published on November 21, 1988. The revision of "Metallographic Examination of Induction Hardened Pearlitic Spheroidal Graphite Cast Iron Parts" was only in accordance with the relevant 1
Mechanical Industry Standard of the People's Republic of China
Pearlite Spheroidal Graphite Cast Iron Parts
Metallographic examination ot induction hardenedpearlitic spheroidal graphite cast iron partsJB/T 9205--1999
Replacement ZB J36 010-88
This standard specifies the technical requirements and corresponding inspection methods for induction quenching metallographic examination of pearlite ductile iron parts, and is applicable to the inspection of the metallographic structure and depth of the hardened layer of ductile iron parts with a pearlite content of not less than 5% after high, medium frequency induction quenching and low temperature tempering (tempering temperature ≤ 200℃).
2 Definitions
This standard adopts the following definitions.
2. [Boundary microstructure
Use pearlite with an area fraction of 20% as the boundary structure. In special cases, other boundary structures may also be used after consultation between the relevant parties. 2.2 Depth of hardened layer
Measured from the surface of the hardened layer of the part to the vertical distance equal to the boundary structure position. 3 Technical requirements
3.1 The surface hardness and depth of the hardened layer of the part shall meet the requirements of the product drawings. 3.2 After the parts are subjected to high and medium frequency induction annealing, the surface shall not be allowed to have defects such as annealing cracks and burns. 3.3 The microstructure of the hardened layer shall be compared and evaluated according to the pearlite ductile iron part induction annealing structure rating chart (Figure 8). The grading description of the microstructure of the hardened layer is shown in Table 1, among which grades 3-6 are qualified. When there are special requirements, it shall be implemented in accordance with the provisions of relevant technical documents. Table 1 Description of the microstructure classification of the hardened layer
Structural characteristics
Coarse martensite, large retained austenite, ledeburite, spheroidal graphite Coarse martensite, large retained austenite, spheroidal graphite martensite, massive retained austenite, spheroidal graphite martensite, a small amount of retained austenite, spheroidal stone fine martensite, spheroidal stone amount
Fine martensite, a small amount of undissolved ferrite, spheroidal graphite Micro-fine martensite, a small amount of undissolved pearlite, undissolved ferrite, spheroidal stone fine martensite, more pearlite, soluble ferrite, spheroidal graphite State Machinery Industry Bureau 1999-06-24 Approval No.
2000-01-01 Implementation
4 Preparation of sample
JB/T 920S-1999
4.1 Sampling: Cut the sample in the middle of the induction hardening area of ​​the part according to the position specified in the technical conditions of the part. 4.2 The polished surface of the sample should be perpendicular to the surface and etched with 2%-5% nitric acid alcohol solution until a clear hardened layer is shown. 4.3 The sample should not change its original structure during the preparation process. Figure 1
Figure 22 level
Figure 33 level
JB/T 9205—1999
Figure 44 level
Figure 55 level
Figure 66 level
5 Inspection method
3B/9205—1999
Figure 7 level
Figure 88 level
5.1 The microstructure of the hardened layer is observed under a metallographic microscope at a magnification of 400 times. 5.2 The depth of the hardened layer is measured under a metallographic microscope at 100 times magnification, see Figure 9. JB/T9205-1999
Figure 9 Standard diagram for measuring the depth of hardened layer
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