JB/T 7162-1993 Rock drilling machinery and pneumatic tools structural steel JB/T7162-1993 standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T7162—93
Rock drilling machinery and pneumatic tools
General technical conditions for structural steel investment castings
Issued on November 21, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on March 1, 1994
Machinery Industry Standard of the People's Republic of China
Rock drilling machinery and pneumatic tools
General technical conditions for structural steel investment castings
Subject content and scope of application
JB/T7162-93
This standard specifies the casting classification, technical requirements, inspection and delivery of structural steel investment castings for rock drilling machinery and pneumatic tools. This standard applies to structural steel investment castings for rock drilling machinery and pneumatic tools. Cited standards
GB222 Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products GB223 Chemical analysis method for steel and alloys
GB228 Metal tensile test method
Casting classification
Metal Charpy (U-notch) impact test method Castings are divided into three categories according to the inspection items, as shown in Table 1. Table 1
Casting categories
(1) Chemical composition; (2) Dimensions; (3) Surface quality: (4) Mechanical properties (, 0, s4, 4): (5) Internal quality (shall comply with the provisions of Article 4.7 of this standard)
(1) Chemical composition, (2) Dimensions, (3) Surface quality; (4) Mechanical properties (.α); (5) Internal quality (shall comply with the provisions of Article 4.7 of this standard)
(1) Chemical composition: (2) Dimensions: (3) Surface quality: (4) Internal quality (shall comply with the provisions of Article 4.7 of this standard) Note: For Class 1 and Class 1 parts, they should be marked in the product drawings, and Class ■ parts are not marked, for example ZG310-570-1, ZG20Cr-1, 4 Technical requirements and inspection
Chemical composition of castings
The chemical composition of castings shall comply with the provisions of Table 2 and Table 3. Table 2
Transfer parts category
ZG310-570
0.42~0.52
0.20~0.45
0.50~0.80
Phosphorus (not more than)
Phosphorus (not more than)
The residual content of nickel, chromium and copper in steel should not exceed 0.3%. Unless otherwise specified in the special technical documents, no analysis will be conducted. Approved by the Ministry of Industry on November 21, 1993
Implemented on March 1, 1994
ZG20Cr
ZG40C:
ZG45Cr
ZG20CrMnMo
0.15~~0.25
0.35~0.45
0.40~~0.50
0.15~0. 25 | | tt | 0.80
0. 90~1. 20
0.80~1.10
0.80~1.10
0.80~1.10
1.10~1.40
0. 20~0. 30
The residual content of iron and nickel in steel should not exceed 0.30%. Except for the special technical conditions, no separate notes shall be made; for parts with qualified machine core performance and parts with qualified machine core performance, the chemical composition is allowed to have the following deviations: C; ±0.01%, Si; ±0.03%, Mn; ±0.05%; Cr; ±0.05%; Mo: +0.05%, -0.02%. 4.2 Inspection of chemical composition
The chemical composition should be inspected by remote furnace.
4.3 Chemical analysis sample
(not more than)
The sampling method of chemical analysis sample shall be in accordance with the provisions of GB222, and it can also be sampled from the casting for determination. The chemical analysis method shall be in accordance with GB223 or other methods with equal accuracy, but the arbitration analysis must be in accordance with the provisions of GB222. 4.4 Mechanical properties
4.4.1 This standard adopts a single molded sample. The pouring system shall comply with the provisions of Figure 1, the tensile test mix shall comply with the provisions of Figure 2, and the impact test specimen shall comply with the provisions of Figure 3.
The tensile test method shall comply with the provisions of GB228, and the impact toughness test method shall comply with the provisions of GB229. 9
Figure 1 Porcelain pouring system
Figure 2 Tensile test specimen
27.5±0,1
JB/T7162-93
Figure 3 Impact toughness test specimen
4.4.2 Mechanical properties The specimen shall be heat treated in the same furnace as the casting it represents. The hardness and mechanical properties after heat treatment shall comply with the provisions of Table 4.
ZG40Cr
ZG45Cr
ZG20Cr
ZG20CrMnMo
Normalizing+
860±16
860±10
870±10
870±10
860±10
860±10
900±10
Positive900±10
Back670±10
900±10
≤197
≤179
Tensile strength.
N/rmm*
470, 7
Flexural strength.
Shrinkage of area
Elongation 6,
Impact toughness 4
4.4.3 Mechanical properties Select 3 samples of each type, of which 2 should be qualified. If the sample itself has defects caused by casting, machining or heat treatment, its test data will be invalid, and the spare sample should be taken for retest. 4.5 Casting size
4.5.1 The size and geometric shape of the casting shall comply with the provisions of the casting drawing, and the deformation deviation of the casting shall be within the casting size tolerance range. 4.5.2 The casting size accuracy is divided into three levels, see Table 5. Basic size
>10~18
>18~30
>30~50
>50~80
High-level precision
Deviation value
General precision
JB/T7162-93
Basic size
Low-level precision
Note: Unidirectional deviation can be taken, and the deviation value is the tolerance value, 4.6 Surface quality
>80~120
>120~180
>180~250
>250~315
>315~400
>400~500
High-level precision
± 0. 405
Stop difference
General accuracy
Low-level accuracy
4.6.1 The inner and outer surfaces of the casting should be cleaned, and the gate should be removed before heat treatment. The gate head should comply with the provisions of the casting drawing or relevant process documents.
4.6.2 Cracks, cold shuts and penetrating defects are not allowed on the casting. 4.6.3 Castings are divided into non-machined surfaces and machined surfaces. The size and number of allowable defects are in accordance with the provisions of Table 6. The maximum depth is allowed to be 2mm, but not more than 1/5 of the wall thickness at that location, and similar defects are not allowed on the corresponding parts on the reverse side. Table 6
Maximum
External dimensions of equal parts
>50~100
>100~260
>260~100
After processing
Non-processing
Number on a 10cm surface
After processing
Non-processing
On a part
Allowed number
After processing
Non-processing||tt ||Medium defect
Concentrated defect
Distance between another defect
①For castings with a maximum outer dimension greater than 100mm, when the diameter of a single hole on the machined surface is ≤1.5mm and the diameter of a single hole on the unmachined surface is ≤2mm, the spacing is allowed to be 5mm.
②On the unmachined and machined surfaces of castings, single holes with diameters not greater than 0.5mm and 0.3mm respectively and depths not greater than 0.3mm are not treated as defects.
③Concentrated defects refer to surface looseness, scars, and holes with a diameter less than 0.5mm (less than 0.3mm on the surface after machining) 4.6.4 On the surface to be machined of the casting, it is allowed to have a concave casting defect that does not exceed the machining allowance. It is also allowed to have a convex defect with a height of no more than 1mm.
4.6.5 On the non-machined surface of the casting, it is allowed to have a concave defect with a depth of no more than 1mm and a convex defect with a height of no more than 1mm.
JB/T 7162—93
The surface roughness of the casting shall comply with the provisions of Table 7. 4.6.6
Roughness grade of equal parts
Surface roughness value R
4.7 Internal quality
4.7.1 The internal quality of the casting shall be regularly inspected and shall comply with the provisions of the product drawings or special technical documents. 4.7.2 The casting must be normalized, annealed, or normalized and high-temperature tempered to eliminate casting stress and improve the organization. 4.7.3
Castings that need to be inspected for decarburization should be specified in special technical documents and drawings. Except for special circumstances, the depth of decarburization should generally comply with the provisions of Table 8.
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Deepness of decarburization on one side
4.8 Defect correction
4.8.1 Castings can be corrected in hot or cold states. Castings that need to be stress-relieved and tempered after correction should be specified in relevant technical documents. 4.8.2 Welding repairs are generally allowed before and after casting processing (castings that are not allowed to be welded should be indicated in special technical documents). Castings that are welded before processing should comply with the requirements of casting drawings, and the parts to be welded should be heat treated again after welding. 5 Delivery of castings
Castings should be treated for rust prevention.
Each batch of castings shall be accompanied by a certificate of conformity, which shall indicate: a.
Product model:
Transfer code and name:
Quantity:
Steel grade:
Casting category:
Heat treatment status:
If the ordering technical conditions stipulate that there are inspection items, the inspection results shall be attached with additional instructions:
This standard is proposed and managed by the Tianshui Rock Drilling Machinery and Pneumatic Tools Research Institute of the Ministry of Machinery Industry. This standard is drafted by Shenyang Pneumatic Tools Factory. The main drafters of this standard are Na Changyou and Xu Li. From the date of implementation of this standard, JB/SQ17-87 & General Technical Conditions for Investment Castings of Rock Drilling Machinery and Pneumatic Tools Structures> will be invalid. 5
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