JB/T 7163-1993 Steel die forging for rock drilling machinery and pneumatic tools
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T7163-93
Rock Drilling Machinery and Pneumatic Tools
General Technical Conditions for Steel Die Forgings
Published on November 21, 1993
Ministry of Machinery Industry of the People's Republic of China
Implemented on March 1, 1994
Machinery Industry Standard of the People's Republic of China
Rock Drilling Machinery and Pneumatic Tools
General Technical Conditions for Steel Die Forgings
Subject Content and Scope of Application
JB/T7163-93
This standard specifies the scope of application, technical requirements, accuracy grades, inspection levels, acceptance rules and inspection methods for steel die forgings for rock drilling machinery and pneumatic tools.
This standard applies to hot die forgings of carbon steel and alloy steel rock drilling machinery and pneumatic tools forged by forging hammers and presses. Unless otherwise specified in the product part drawings, technical conditions (or order contracts), this standard shall apply. 2 Reference standards
GB6394
3 General provisions
Metal Brinell hardness test method
Metal average grain size determination method
3.1 Marking codes and names of forging drawing dimensions (see Figure 1): H-thickness dimension (dimension across the parting surface); B,
-length or width dimension;
-internal shape dimension, which can be classified as B, (length or width dimension): dimension from center or center line) to outer edge:
-height dimension:
center distance.
3.2 The codes and names of forging material groups are divided into two groups according to the chemical composition of steel: M, steel with carbon content <0.65% and total content of alloy components manganese, chromium, nickel, molybdenum, vanadium and tungsten <5%; JB/T7163-93 approved by the Ministry of Machinery Industry on November 21, 1993 and implemented on March 1, 1994, with carbon content ≥0.65% and total content of alloy components manganese, chromium, nickel, molybdenum, vanadium and tungsten ≥5%. 3.3 The code for the shape category of forgings is S. According to the complexity of the forgings, they are divided into Si, St, S, and the calculation method is as follows: Forging volume (or weight)
Forging volume (or weight) after simplification
S,S0.20.4
The simplified volume of the forging is the volume of the smallest circumscribed cylinder or circumscribed regular hexahedron simplified according to the length, width and thickness of the forging (National 2). Figure 2
3.4 Forging parting forms are divided into two types according to whether they are symmetrical or not: F, - symmetrical parting (parting form without horizontal pushing force), see Figure 3a: F,
- asymmetrical parting (parting form with horizontal pushing force), see Figure 3b: b
3.5 Lookup method of forging dimension tolerance table
Taking forging thickness dimension tolerance table 3 or table 4 as an example, the lookup method is as follows: First, find the weight range in the "forging weight\ column, and then go to the right to find it in the "material group" column. If the "material group" is M, then go directly to the right to find it in the "complex shape category\ column. If the "material group" is M:, then follow the oblique line from the intersection of the weight classification line and the M: line to the M: line, and then search to the right along the horizontal line. Then use the same method to find the tolerance column according to the "complex shape category" is S, or St, S2
JB/T7163-93
, and finally find the tolerance according to the maximum thickness of the forging (the table lookup method for the length, width, height tolerance of the forging and the center error of the forging is similar).
4 Forging accuracy level and inspection level
4.1 Forging accuracy is divided into two levels:
Level 1 has higher accuracy, generally used in places where most of the forging surface is no longer machined and high accuracy is required, accuracy level E:
Level 2 has suitable The accuracy is mostly used in occasions where the accuracy requirements for forgings are not very high, ordinary grade F. All ungraded tolerances or allowable values are applicable to both grade 1 and grade 2 parts. In grade 2 accuracy forgings, if higher accuracy is required for individual parts, the requirement can be implemented according to grade 1, but it should be marked at the appropriate position in the part.
After the accuracy of the forging is determined, it should be indicated in the part drawing in the manner specified in Article 4.3 of this standard. If it is not indicated, the grade 2 part shall be treated as such.
4.2 Forgings are divided into four grades according to the design requirements of product parts, working characteristics and uses (or order requirements) and the items to be inspected, see Table 1.
Rubber test grade
Grain size
Note: "" in the table indicates an item with test. Purpose||t t||Carbon content, grain size, metallographic structure: 2 pieces are taken from the same steel grade, same batch material, same heat treatment specification and same furnace
After the inspection grade is determined, it shall be indicated in the forging drawing in the manner specified in Article 4.3 of this standard. If not specified, it shall be treated as Grade IV.
4.3 For examples of grade and level marking, see Articles 4.3.1, 4.3.2 and 4.3.3 of this standard. 4.3.1 If the forging precision is Grade 1 and hardness and grain size (Grade I) inspection is required, it shall be marked as: Grade 1-Grade I forgings-JB/T7163. 4.3.2 If the forging precision is Grade 1 and there is no inspection requirement, it shall be marked as: Grade 1 forgings-JB/T7163. 4.3.3 If the forging precision is Grade 2 (or there is no precision level requirement). There is no inspection requirement. Then No marking, 5 Technical requirements
The pin number of the profile used for forgings must comply with the provisions of the product part drawings. 5.1
5.2 The profile used for plated parts must be hot-pressed materials. 5.3 The profile used for forgings must be accompanied by a certificate of inspection and must be re-inspected at the factory (including dimensional tolerances) before it can be used. 5.4 The burrs on the ends of the profile used for forging head forgings must be removed. 5.5 During the production of forgings, the heating, initial forging overflow, final forging temperature and cooling conditions after forging shall be carried out in accordance with the forging process regulations (or order contracts).
5.6 The overburned burrs produced when the blanks are heated shall be treated as a degree. 5.7 The single-side machining allowance of the section shall comply with the provisions of Articles 5.7.1 and 5.7.2 of this standard. 5.7.1 The single-side machining allowance of forgings shall comply with the provisions of Table 2. 5.7.2 When the surface roughness value of the part is 1.6μm or higher, the single-side machining allowance is increased by 0.3~0.5mm. 3
Maximum width
Maximum thickness
>40~63
>63~100
>100~160
>160~250
JB/T7163-93
Table 2 Single-side machining allowance
Maximum length of longitudinal elongation forgings
Maximum diameter of rotationally symmetrical forgingswww.bzxz.net
>63~100
>100~160
>160~250
>250~400
The tolerances of the dimensions in the thickness direction (Fig. 1) of forgings shall comply with the requirements of Clauses 5.8.1 and 5.8.2 of this standard. 5.8
>400~630
The maximum thickness dimension tolerance shall comply with the provisions of Table 3 (Grade 1) or Table 4 (Grade 2) according to the forging accuracy level. The tolerance found is applicable to all thickness dimensions in 5.8.1
.
5.8.2 The positive and negative deviations of the center-to-outer edge dimension shall be 2/3 of the positive and negative deviation values of the thickness dimension. Table 31 Thickness Tolerance Table for Grade 1 Forging Weight
>1. 0~2. 5
>2. 5~5. 0
>10~16
>16~25
>25~40
Material Group
Complex Shape Category
>32~100
>100~160
5.9 The tolerances of length, width and height (Fig. 1) of forgings shall comply with the provisions of Articles 5.9.1 to 5.9.4 of this Standard. Inch
>160~250
5.9.1 The tolerances of length and width shall comply with the provisions of Table 5 (Grade 1) or Table 6 (Grade 2) according to the accuracy level of forgings. For the convenience of inspection, a larger single length dimension tolerance and a single width dimension tolerance can be taken. 5.9.2 For the positive and negative tolerances of the internal dimensions, the positive and negative deviations of the length and width dimensions shall be distributed as +1/3 and -2/3. Weight of warp parts
>2.5~5.0
>10~16
>16~25
>25~40
General weight of parts
>1.0~2.5
>2.5~5.0
>10~20
>20~50
Material group
Material group
JB/T7163-93
Table 42-level thickness tolerance table
Shape complexity category
>32~100
1-level length, width, height tolerance table
Shape complexity category
>100~160
>160~250
>32~100>100~160>160~25>250~40d>400~630m
Forging weight
>1. 0~2. 5
>2. 5~5. 0
>10~20
>20~50
Material group
JB/T 7163-93
Table 62 Length, width and height tolerance table
Complex shape category
>32~100>100~160
>160~250>250~40d>400~630
5.9.3 For the tolerance of height dimension, refer to Table 5 (or Table 6) for height dimension, and take 1/2 value as its positive and negative deviation value. 5.9.4 For the positive and negative deviation of the dimension from center to outer edge, refer to Table 5 (or Table 6) for length and width dimension, and take .2/3 value as its positive and negative deviation value.
5.10 The allowances and tolerances of special parts of forgings may be implemented in accordance with the provisions of Articles 5.10.1 and 5.10.2 of this standard. 5.10.1 For forgings with high platform (Fig. 4), when the height of the boss is greater than the diameter of the platform end or the calculated diameter (d1.13VF, F is the cross-sectional area of the platform end), it is called high self, and its surface machining allowance can be increased by 1% of the surface base, and its thickness dimension tolerance value is the original positive deviation unchanged, and the negative deviation is the sum of 1/3 of the total allowance of the high platform end face and the original negative deviation. 5.10.2 For forgings with thin disk (Fig. 4), when (D-d)/e≥4, it is called thin disk (when the disk is non-circular, D is the calculated diameter, when there are bosses on the upper and lower parts of the disk, d takes the larger value), all thickness dimension tolerances of the forging are taken as negative deviation unchanged, and the positive deviation is increased by 0.3. 5.11 For long rod neck forgings (Fig. 5), the positive deviation of its maximum thickness H is increased by 0.3 times. When the head thickness H,120~180
JB/T 7163-93
>180~240
>240~315
Inside (p)
>315~400
>400~500
<500~630
Forging height
Slope a
·JB/T7163-93
>60~120
5.14 The fillet radius rzr in the thickness direction of forgings, as well as the cone diameter d,, hole diameter dz, rib width b, and groove width b, (Figure 8) shall comply with the provisions of Articles 5.14.1 to 5.14.7 of this Standard. When there are no special requirements in the product drawings, r,,, are allowed to take the values in Table 10. Table 10
>10~16
>16~25
>25~40
>40~63
>63~100
>100~160
by/hud:/h
When the sum of the machining allowance and the part corner width is less than r, it is allowed to increase the machining allowance to make it equal. When the machining hole diameter is less than 40, it is allowed not to forge or not to punch after forging. When the hole diameter d; and the rib width 6, are less than the values specified in Table 10, it is allowed to forge shallow or negotiate. When the cone diameter d, is less than the values specified in Table 10, it is allowed to increase d, or negotiate. When the groove bottom width is less than 2, or the rib width is ≤2r, the sugar bottom or rib top should be made into a semi-circular shape. mm
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