This standard is applicable to the determination of microstructure, grain size and non-metallic inclusion level of cast carbon steel for general engineering under metallographic microscope. GB/T 8493-1987 Metallographic structure of cast carbon steel for general engineering GB/T8493-1987 Standard download decompression password: www.bzxz.net

UDC 621-741.4:534.24
National Standard of the People's Republic of China
GB 8493--87
Metallograph of cast carbon steels forgeneral engineering purposes1987-12-28
Issued by the State Bureau of Standards
Implemented on August 1, 1988
National Standard of the People's Republic of China
Metallograph of cast carbon steels forgeneral engineering purposesMetallograph of cast carbon steels for general engineering purposesUDC 621.T41.4
GB8493-87
This standard applies to the identification of microstructure and the determination of grain size and grade of non-metallic inclusions of cast carbon steels for general engineering purposes under a metallographic microscope.
tSampling
1. Samples for heavy metallographic examination are cut from mechanical properties test blocks or samples. 1.2 Samples with special requirements can be agreed upon by both parties. 1. The cutting and preparation of samples should not be affected by overheating or deformation. 2 Microstructure
The microstructures of this standard are etched with 2% to 4% nitric acid alcohol solution. First, make a comprehensive observation of the grinding surface of the sample from the edge to the center, and then determine its microstructure according to the majority of the viewing field. 2.1 ZG200 = 400 cast steel microstructure as shown in Table 1. Table 1 Microstructure of different heat treatment specifications
Abnormal
Non-positive band
Non-positive band
Non-positive band
Heat treatment brownness,
ACT-AC,
AC + 5 ~150
AC+0 above
AC,-AC,
AC + 50 150
AC,+10 above
National Bureau of Standards 18 Ting- 12 - 2 Quasi-microstructure and its characteristics
Structure + blocky ferrite + pearlite
Ferrite + discontinuously distributed pearlite + residual cast structureFerrite + discontinuously distributed pearlite (structure coarsening)Ferrite + pearlite + residual cast structure
Ferrite + pearlite
Linear ferrite + pearlite + soul structure (structure coarsening) Figure number
Magnification|| tt||1988-08-01 implementation
GB8493-87
2.2 ZG23-450 cast steel microstructure Table 2Www.bzxZ.net
GB8493--87
Table 2 Microstructure of different heat treatment specifications
Non-normal band
Non-normal fee
Non-normal mushroom
Abnormal
Heat treatment temperature, C
AC,-AC
AC - + 50 - 151
AC++ 150l on
AC - 50-T50
AC, +ISU with H
Microstructure and characteristics
Widmanstätten structure + bulk ferrite + pearlite ferrite + network-distributed pearlite + residual anterior structure ferrite + network-distributed pearlite
chain rest + network-distributed pearlite (weaving coarsening) ferrite 4 pearlite + residual state structure
ferrite + lamellar body
minan body + Hu Guangben + Wei Wu structure (organization phase transformation) Figure 8
so big night number
100 ×
GB 8493—87
GB 8493--87
2.3ZG270-500 cast steel microstructure is shown in Table 3. Table 3 Microstructure of different heat treatment specifications
Non-stop band
Non-positive band
Non-normal
Non-stop
Non-positive band
Non-positive band
Heat treatment temperature, r
AC,~AC,
AC, + 50 ~ 150
A150 with
AC- + 50 ~ 150
AC,+I5a with L
AC,-AC,water+[uk
AC,+3-50 water itch+tempering
AC,+50 above water ze+tempering
Microstructure and characteristics
Pearlite+Merck group+massive ferrite
Ferrite+light body+residual cast structure
Ferrite+ Net-shaped pearlite
Ferrite + net-shaped pearlite (organization rooting)Ferrite + pearlite + residual continuous structure
Ferrite + pearlite
Ferrite + pearlite + Widmanstätten structure (organization coarsening)Flaminite F-soluble ferrite
Tempered ferrite
Tempered ferrite (organization coarsening
Enlarged number
GB 8493—87
GB B493-67
ZG310-570 cast steel microstructure is shown in Table 4. CB B499—87
Table 4 Microstructure of different heat treatment specifications
Abnormal
Abnormal
Abnormal
Abnormal
Abnormal
Abnormal
Heat treatment temperature, ℃
ACI~AcI
AC + 50 ~150
AC;+150 and above
AcI~Ac1
AC,+50~150
AC,+150 and above
AC,~AC, water flow + tempering
AC,+30~50 water itch + tempering
A:+ Tempering at water content above 50
Microstructure and characteristics
Pearlite + ferrite Part of ferrite is distributed in a network along the boundary of austenite
Pearlite + ferrite + or retained as-cast structure
Pearlite + ferrite
Pearlite + ferrite (coarsening of structure)
Pearlite + ferrite + residual as-cast structure
Pearlite + ferrite
Pearlite + ferrite with a network distribution (coarsening of structure) Tempered troostite + undissolved ferrite
Tempered troostite
Tempered troostite (coarsening of structure)
Magnification
500 ×
GE 8493-87
GB8493—87
ZG The microstructure of 340-640 cast steel is shown in Table 5. GB B493--87
Table 5 Microstructure of different heat treatment specifications
Abnormal
Abnormal
Abnormal
Abnormal
Abnormal
Heat treatment temperature,
AC,-ACs
AC/ + 50 ~ 150
AC, + 150 With H
ACT-AC,
AC , + 50 ~ 150
AC, above +150
AC, ~AC, water quenching + tempering
AC, +30~50 water quenching + tempering
AC, above +50 water quenching + tempering
Microstructure and characteristics
Pearlite + ferrite with network distribution
Pearlite + ferrite + residual cast structure
Pearlite + ferrite
Pearlite + ferrite (organization)
Pearlite, ferrite + residual cast structure
Pearlite + ferrite
Tempered troostite+free ferrite
Tempered troostite (organization coarsening)
Magnification
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.