This standard specifies the metallographic inspection and determination method for the metal layer of steel parts. This standard applies to the preparation of samples, the structure of the infiltration layer, the depth of the infiltration layer (not applicable to steels with no obvious boundary between the infiltration layer and the matrix) and the inspection and determination of microhardness of steel parts after chromizing, aluminizing, zincizing, vanadiumizing, titaniumizing and niobiumizing. JB/T 5069-1991 Metallographic inspection method for infiltration metal layer of steel parts JB/T5069-1991 Standard download decompression password: www.bzxz.net
This standard specifies the metallographic inspection and determination method for the metal layer of steel parts. This standard applies to the preparation of samples, the structure of the infiltration layer, the depth of the infiltration layer (not applicable to steels with no obvious boundary between the infiltration layer and the matrix) and the inspection and determination of microhardness of steel parts after chromizing, aluminizing, zincizing, vanadiumizing, titaniumizing and niobiumizing.

Mechanical Industry Standard of the People's Republic of China
JB/T 5069--91
Metallurgical Inspection Method of Infiltrated Metal Layer of Iron and Steel Parts
Published on 1991-06-11
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on 1992-07-01
Mechanical Industry Standard of the People's Republic of China
Metallurgical Inspection Method of Infiltrated Metal Layer of Iron and Steel Parts
1 Subject Content and Scope of Application
This standard specifies the metallographic inspection and determination method of infiltrated metal layer of iron and steel parts. JB/T5069---91
This standard is applicable to the preparation of samples, organization of infiltrated layer, depth of infiltrated layer (not applicable to steels without obvious boundary between infiltrated layer and substrate) and inspection and determination of microhardness of iron and steel parts after infiltrating chromium, aluminizing, zincizing, vanadiumizing, titaniumizing and sawing. 2 Reference standards
GB 6462
GB 9451
GB9790
Method for measuring the thickness of metal and oxide coatings on cross-sections Microscope Determination of the total hardened layer depth or effective hardened layer depth on thin surfaces of steel parts Vickers and Knoop microhardness test for metal coatings and other related coatings ZBJ36 011
Technology and quality inspection of hot-dip aluminum in steel.
3 Terms
3.1 Depth of infiltration layer
The distance from the surface of the layer to the interface line of the infiltration layer. 3.2 Interface line of infiltration layer
The boundary line between the infiltration layer and the base metal shown by the metallographic specimen under the action of the etchant. 4 Sample preparation
4.1 Sample cutting
4.1.1 The sample should be taken from a representative part of the infiltration metal part and cut vertically on the surface of the infiltration layer. 4.1.2 For extremely thin (<5um) infiltrated metal layers, prepare oblique cross-section specimens according to GB9451. 4.1.3 To avoid deformation and collapse of the infiltrated metal layer of hollow parts, resin fillers should be used to pour into the solid body first, and then cut into specimens after solidification. 4.1.4 Substitute specimens of the same steel grade and process can be used. 4.1.5 The cut specimens must be water-cooled to avoid changes in the structure. 4.2 Clamping and Mounting
4.2.1 Regular specimens can be clamped and ground with a fixture. In order to separate the infiltrated metal layers of two specimens, nickel or copper sheets should be placed between the specimens. 4.2.2 Irregular specimens are ground after inlaying. Extremely thin infiltrated layers can be plated before inlaying. 4.3 Grinding and Polishing
4.3. The specimens are lightly ground with grinding wheels, pre-grinding discs and sandpaper. The grinding direction should be 45° to the infiltrated layer. Change the sandpaper and turn 90 degrees to still be 45° to the infiltrated layer.
4.3.2 When polishing, first use polishing powder or diamond polishing paste, and finally polish with clean water. 4.4 Before etching, check the prepared metallographic specimens for pores, cracks and bonding surfaces according to ZBJ36:011. Approved by the Ministry of Machinery and Electronics Industry on June 11, 1991 and implemented on July 1, 1992
See Table 1 for etching agents and their uses.
No.
Nitric acid (-1.42) 2~3ml
Absolute alcohol
97~98 mL
Potassium ferrocyanide
10--20g
Potassium hydroxide 10-~20g
100mL
Potassium permanganate
Sodium hydroxide
Citric acid
100mL
90ml
Nitric acid (d= 1. 42) 3 mL
Hydrogen sulfoxide
Absolute alcohol
Sodium hydroxide
Piric acid
Amyl alcohol
Nitric acid
5-layer tissue
3~10 mL
9?mL
100mL
50mL
(d- 1. 42)0. 2 mL
JB/T 5069--91
Table 1
Use conditions
Wipe
60-70℃
1~2 min
Wipe
Add 5 times of water to dilute and soak
5s each time, etch multiple times
The sample displayed by the etchant is magnified 200~800 times with an optical microscope to examine the organization. The various phases displayed by etching of the carburized layer of different steel grades and processes are shown in Table 2 and Figures 1~17. Table 2
Proverb injection scheme
Base steel type
Pure iron
Infiltrant and composition
Chromium powder 50%
Aluminum oxide 50%
Ammonium chloride 1% (additional)
Chromium powder 50%
Aluminum oxide 50%
Ammonium chloride 1% (additional)
Chromium powder 70%
Aluminum oxide 30%
Ammonium chloride 1% (additional)
Borax 85%
(Dichromium trifluoride + aluminum powder)
Process
Vacuum method
1160℃
1. 33--13. 3 Pa
Powder method
1180
Furnace
Powder method
1050℃
Furnace
Molten salt method
960℃
Applicable pressure
Steel matrix material and latent zinc layer, titanium infiltration, chromium infiltration layer, vanadium infiltration layer
Cleaning vanadium infiltration, chromium infiltration layer
Aluminum layer
Zinc layer
Zinc layer
Forming phase
(Cr,Fe)sCr|| tt||Crz(CN)
(Cr、Fe)2C
(Cr.Fe).Cs
Cra(CN)
(Cr、Fe)uCe
(Cr.Fe),Cr
Fesc
(Cr,Fe)C.
(Cr,Fe),Cs
Fesc
Drawing number
Participating elements Matrix steel grade
GCt15
Gcr 15
Gcr15
Potent and composition
Fe-lead powder 100%
(50% aluminum)
1% ammonium chloride (additional)
Fe-aluminum powder 85%
(50% aluminum)
Tri-supported aluminum
1% ammonium chloride
Molten aluminum
Zinc powder
100%
Molten zinc
Molten zinc
Borax 85%
Vanadium pentoxide| |tt||Aluminum powder 5%
(Borax + Chloride)
55%~60%
(Titanium dioxide + aluminum powder)
Chemical cutting 10%-15%
Borax
Rao powder
J3/T5069-91
Continued Table 2
Process
Powder method
950℃
Powder method
Heat method
750c10min
Hot dip diffusion method.
780℃ diffuse 30min
950C
8h diffusionbZxz.net
Powder method
380r:
Heat method
450℃
1min
Hot dip method
520--530℃
3nin
Molten salt method
96 0℃
Molten salt method
960℃
Molten salt removal
960℃
Shaped frame
t(FeAl2)
Br(FeAl)
, among which there are needle-shaped B
(FesAl)
main, (FeAl) among which there are rod-shaped
Al.Cs
Ha(FeAl)
a, among which there are needle-shaped positive
(FeaAl)
n(Fe?Als)
n+-B(Fe2A+FeAl,)
Ba(FeAr)
a, among which there are needle-shaped
(FerAl)
n++(Zn+FeZn)
8(FeZn)
n(Zn)
n+(Zn+FeZns)
&r(Fezn)
Y(FeZne)
n(Zn)
n+$(Zn+Fens)
(FeZnt)
V.cs
Vic,
Figure number
sU/T 508g)
Figure
Slow single dose: 1! 2×500
Figure 2 Involving three doses: 1+2+×500
Figure 3 Estimated chronic system: 1+2(3)×500
5069—91
Figure 4: Lead erosion agent: 1+2+4×800
ground.5
Hong Kong lead, erosive agent: 5X400
Figure 6
13/r508991
Haipei
mother certificate
Figure sales promotion, 5
X800
zinc-chasing agent: 6X250
Figure 9
JB/T5069—91
Figure 10: Zinc-purifying slow-acting agent: 7×500
Figure 11: Zinc-related, erosive agent: F, X250
Figure 12: Inheriting the traditional agent: 1+2+4
JB/T 5069--91
Figure 13 Capital Needle Grant Debt Pair, 1+2+4×860
Figure! Iron Infiltration Micro-agent: 1
Figure 15 Addition of Erosion Agent, "×0
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