Some standard content:
Mechanical Industry Standard of the People's Republic of China
Wear-resistant white cast iron parts for pumps
1 Subject content and scope of application
JB/T 6880.3-93
This standard specifies the brand, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of wear-resistant white cast iron parts for pumps (hereinafter referred to as castings).
This standard applies to sand castings for centrifugal pumps and reciprocating pumps. Reference standards
GB5612
GB8263
GB9439
GB/T11350
GB/T11351
3 Grade
Method of expressing cast iron grades
Surface roughness comparison sample casting surface
Technical conditions for wear-resistant white cast iron
Gray cast iron parts
Machining allowance of castings
Tolerance of casting weight
The casting grades shall comply with the provisions of Table 1 and Chapter 2 of GB8263. The grades in Table 1 comply with the provisions of GB5612. 4 Technical requirements
4.1 Production method
The production method shall comply with the provisions of Article 3.1 of GB8263. The heat treatment specifications for castings can refer to Appendix A (reference) of this standard and Appendix A of GB8263.
4.2 The chemical composition shall comply with the requirements of Table 1 and Article 3.2 of GB8263. Table 1 Brand and chemical composition of castings
KmTBMn2W2
KmTBMn5Mo2
KmTRCr15Mo3
KmTBMn2W2
KmTBMn5Mo2wwW.bzxz.Net
KmTBCr15Mo3
Approved by the Ministry of Machinery Industry on July 13, 1993
Chemical composition%
4.0～~6.0
Chemical composition
14. 0--19.0
Implemented on July 1, 1994
JB/T6880.3-93
Metallographic structure
Under normal circumstances, metallographic structure is not used as the basis for acceptance. If the purchaser has requirements for the metallographic structure, it shall comply with the provisions of Table 2 and Appendix B of GB8263.
Table 2 Metallographic structure of castings
KmTBMn2W2
KmTBMn5Mo2
KmTBCr15Mo3
4.4 Mechanical properties
Eutectoid carbide (Fe.Mn.W>3C+spherulite++sorbite (no graphite)
Eutectoid carbide (Fe.Mn.W)3C+martensite+retained austenite
Eutectoid carbide (Cr.Fe)7C3+austenite and its transformation products
Eutectoid carbide (Cr.Fe)7C3+secondary carbide+martensite+retained austenite|| tt||The hardness of the casting shall comply with the provisions of Table 3 and Article 3.4.1 of GB8263. In addition to hardness, the other mechanical properties of the casting, if required by the purchaser, shall be agreed upon by the supply and demand parties through test methods and performance indicators. Table 3 Hardness values of castings
KmTBMn2W2
KmTBMn5Mo2
KmTBCr15Mo3
4.5 Geometric shape and size
≥350
≥520
≥490
The geometric shape and size of the casting shall comply with the requirements of the drawing. 4.6 Dimension tolerance
The dimensional tolerance of general parts shall not be less than that specified in Table 4. Table 4 Dimension tolerance of general parts of castings
Castings Basic size
>10~16
>16~25
>25~40
>40~63
>63~100
>100~160
>160~250
>250--400
>400~630
>630~1000
General parts
Dimension tolerance
≤650
Wall thickness dimension tolerance
Casting size
≥600
Basic casting size
>10001600
>1600~2500
>2 500~4000
JB/T6880.3-93
Continued Table 4
General Parts
Dimension Tolerance
Wall Thickness Tolerance
Casting Dimensions
When the dimension tolerance specified in Table 4 cannot meet the requirements, the tolerance grade that can be achieved by the process specified in Table A1 or Table A2 in Appendix A of GB6414 shall be referred to, and shall be indicated in the drawing or the agreement agreed upon by both parties. The dimension tolerance of the flow-through parts shall comply with the following provisions: 4.6.3
The dimension tolerance of the impeller shall comply with the provisions in Figure 1 and Table 5; the dimension tolerance of the volute body shall comply with the provisions in Figure 2 and Table 6; the dimension tolerance of the remaining flow-through parts of the casting shall comply with the provisions in Table 7. Figure 1
Table 5 Dimension tolerances of various parts of impeller
Dimension tolerance
Dimension tolerance
Water inlet diameter
Water outlet width
Dimension tolerance
Dimension tolerance
JB/T 6880.393
Dimension tolerance of volute body
Casing cavity
Width b\
Outer dimensions of jacket volute
Note; 1) For double volute products, the volute cavity width refers to the jacket volute cavity width; for single shell volute products, the volute cavity width refers to the pump body and pump cover volute cavity width.
4.7 Misalignment
JB/T6880.3-93
Dimensional tolerance of the flow-through part of castings
Basic dimensions of castings
Dimensional tolerance of the flow-through part
The misalignment value of castings shall be within the dimensional tolerance specified in Table 4, Table 5, Table 6 and Table 7. When the misalignment value is further restricted, it shall be indicated in the drawing or agreement.
4.8 Machining allowance
The machining allowance of castings shall comply with the relevant provisions of GB11350. The machining allowance shall be selected from the appropriate machining allowance grade in Table 1 of GB11350 according to CT13 grade. Special requirements shall be indicated in the drawing or technical documents (including agreement). Casting weight tolerance
The casting weight tolerance shall comply with the relevant provisions of GB/T11351. Tolerance grade of casting weight. Impeller shall not be lower than MT11 grade, and other castings shall not be lower than MT13 grade.
When the upper and lower deviation requirements of casting weight are not equal or need to be further stringent, it shall be indicated in the drawing or agreement. 4.9.2
When the weight tolerance of casting is used as the basis for acceptance, it shall be indicated in the drawing or agreement. Surface quality
Surface misalignment of castings·If not marked on the drawing, it shall not be lower than the provisions in Table 8. Table 8 Surface roughness of various parts of castings
Maximum size of castings
Roughness
Flow parts
Any size
≤500
Molding sand and core sand on castings shall be cleaned. Casting risers, burrs, fleshy, scars, sticky sand, etc. shall be removed and smoothed. 4.10.2
Castings are not allowed to have cracks, cold shuts, shrinkage and other defects that affect performance. After the castings are processed, the following types of pump parts are not allowed to have residual casting defects, and welding is not allowed: dynamic friction parts, such as the sleeve where the stuffing is installed, the inner hole of the cylinder body and other friction surfaces; dynamic sealing parts, such as sealing surfaces of sealing rings and balance discs; c. Parts with high safety requirements.
4.12 Special requirements
JB/T 6880.3-93
If the purchaser has requirements for water pressure test, air pressure test, non-destructive testing, etc., it should be indicated in the drawing or agreed upon in the order agreement. 4.13 Repair of defects
4.13.1 Welding repair is allowed for castings provided that the strength in use is ensured and the final quality of the pump parts is not affected by welding repair of castings. Welding repair shall strictly comply with the welding repair process.
4.13.2 Casting defects on the machined surface and non-machined surface of castings may be repaired with metal fillers if they do not involve strength and the repair can meet the service life. Repair shall strictly comply with the repair process.5 Test method
5.1 The finished product samples for chemical composition analysis shall be sampled from the same melting and the same ladle. For cupola and arc melting, the second package of molten iron shall be used as the sample: there is no limit on the number of sampling packages for power frequency furnace melting.5.2 The hardness test and hardness test method of castings shall comply with the provisions of Chapter 4 of GB8263. 5.3 In addition to hardness, if the purchaser has requirements for other mechanical properties of castings, the test method shall be carried out according to the agreement agreed upon by the supply and demand parties. 5.4 The metallographic inspection test block is cast at the same time as the casting, or it can be taken from the casting. The test block needs to be heat treated together with the casting. 5.5 For the inspection of the geometric shape and size of the casting, the inspection gauge of corresponding accuracy should be selected. For the parts or related dimensions that cannot be directly inspected by the gauge, the template or the line inspection can be used. 5.6 The method for determining the nominal weight of the casting shall comply with the provisions of Article 3.2 of GB/T11351. The surface roughness inspection of the casting shall be carried out according to the comparison sample selected in GB6060.1. 5.7
5.8 The inspection of the surface defects of the casting shall comply with the provisions of Article 6.11 of GB9439. 5.9 Inspection for special requirements In accordance with the provisions of Article 4.12 of this standard, the inspection shall be carried out in accordance with the agreement or relevant regulations agreed upon by the supply and demand parties. 5.10
Inspection of repair of casting defects shall comply with relevant regulations. Inspection rules
The inspection rights, inspection locations and batch division of castings shall comply with the provisions of Articles 6.1, 6.2 and 6.3 of GB9439 respectively. 6.2 For hardness inspection, if the inspection result does not meet the requirements due to one of the following circumstances, the inspection result shall be invalid: a.
The test block or casting is improperly installed on the hardness tester or the hardness tester is improperly operated; the test block is improperly prepared;
The test block or casting has casting defects at the measurement point. e.
6.3 For hardness inspection, one casting or one test block shall be tested for each batch. 6.4 For the inspection of casting hardness, three points shall be measured at one place (or one test block) first. If the average value of the hardness of the three points meets the requirements, the batch of castings is qualified. If it does not meet the requirements, two more places (or two other test blocks) shall be measured. If one of the places (or one test block) does not meet the requirements, the batch of castings shall be unqualified.
6.5 The metallographic structure inspection of castings shall be agreed upon by the supplier and the buyer. 6.6 The geometric shape, size and tolerance of castings shall be inspected in accordance with the requirements of Articles 4.5 and 4.6. The first batch of castings and important parts shall be inspected piece by piece according to the drawings. General castings and castings produced by methods to ensure dimensional stability can be sampled. The sampling method shall be agreed upon by the supplier and the buyer.
The misshape value shall be inspected piece by piece in accordance with the requirements of Article 4.7. The machining allowance shall be inspected in accordance with the requirements of Article 4.8. The inspection rules shall be in accordance with the provisions of Article 6.6. 6.8
The weight tolerance of castings shall be sampled in accordance with the requirements of Article 4.9. The surface quality shall be inspected piece by piece in accordance with the requirements of Article 4.10. The evaluation method of the roughness of the casting surface shall comply with the provisions of the relevant standards. 6.10
Inspection of casting defects shall be carried out piece by piece in accordance with the requirements of Article 4.11. 6.11
: Inspection of special requirements shall be carried out piece by piece in accordance with the requirements of Article 4.12. 6.13
Inspection of casting repair shall be carried out piece by piece in accordance with the requirements of Article 4.13. 29
JB/T6880.3-93
Acceptance items. Generally, only the following items are accepted: a.
Geometric dimensions;
Surface quality;
Casting defects;
Hardness;
Items required in the drawings;
Other items agreed upon in the agreement between the supplier and the buyer. Marking, packaging, transportation, storage
The marking, packaging, transportation and storage of castings shall comply with the provisions of Chapter 7 of GB9439. 30
JB/T6880.3-93
Appendix A
Reference specification for heat treatment of wear-resistant white cast iron castings for pumps (reference part)
A1 The heat treatment specification for wear-resistant white cast iron castings is related not only to the chemical composition of the castings, but also to factors such as its structure, wall thickness, furnace loading and use conditions. Therefore, in actual production, the heat treatment specification for castings can be formulated according to specific circumstances by referring to Table A1 and Appendix A of GB8263. Heat treatment reference specification for wear-resistant white cast iron parts for pumps Table A1
KmTBMn2W2
KmTBMn5Mo2
KmTBCr15Mo3
Softening annealing process
920~960℃ insulation for 3~
6h, furnace cooling to 700~
750℃ insulation for 48h, then
furnace cooling
920~970℃ insulation for 3
>6h, air cooling after furnace removal
Fire process
180~200℃ insulation for 4
~6h, air cooling after furnace removal
Note; 1) "Maximum section size" can be understood as the maximum section without pearlite structure during continuous cooling. Additional Notes:
This standard was proposed and managed by Shenyang Pump Research Institute. This standard was drafted by Shijiazhuang Pump Factory. The drafter of this standard was Zhang Chongen.
Maximum cross-sectional size 13-93
Appendix A
Reference Specification for Heat Treatment of Wear-Resistant White Iron Castings for Pumps (Reference Parts)
A1 The heat treatment specification for wear-resistant white castings is related not only to the chemical composition of the castings, but also to factors such as their structure, wall thickness, furnace loading and use conditions. Therefore, in actual production, the heat treatment specification for castings can be formulated according to specific circumstances by referring to Table A1 and Appendix A of GB8263. Heat treatment reference specification for wear-resistant white cast iron parts for pumps Table A1
KmTBMn2W2
KmTBMn5Mo2
KmTBCr15Mo3
Softening annealing process
920~960℃ insulation for 3~
6h, furnace cooling to 700~
750℃ insulation for 48h, then
furnace cooling
920~970℃ insulation for 3
>6h, air cooling after furnace removal
Fire process
180~200℃ insulation for 4
~6h, air cooling after furnace removal
Note; 1) "Maximum section size" can be understood as the maximum section without pearlite structure during continuous cooling. Additional Notes:
This standard was proposed and managed by Shenyang Pump Research Institute. This standard was drafted by Shijiazhuang Pump Factory. The drafter of this standard was Zhang Chongen.
Maximum cross-sectional size 13-93
Appendix A
Reference Specification for Heat Treatment of Wear-Resistant White Iron Castings for Pumps (Reference Parts)
A1 The heat treatment specification for wear-resistant white castings is related not only to the chemical composition of the castings, but also to factors such as their structure, wall thickness, furnace loading and use conditions. Therefore, in actual production, the heat treatment specification for castings can be formulated according to specific circumstances by referring to Table A1 and Appendix A of GB8263. Heat treatment reference specification for wear-resistant white cast iron parts for pumps Table A1
KmTBMn2W2
KmTBMn5Mo2
KmTBCr15Mo3
Softening annealing process
920~960℃ insulation for 3~
6h, furnace cooling to 700~
750℃ insulation for 48h, then
furnace cooling
920~970℃ insulation for 3
>6h, air cooling after furnace removal
Fire process
180~200℃ insulation for 4
~6h, air cooling after furnace removal
Note; 1) "Maximum section size" can be understood as the maximum section without pearlite structure during continuous cooling. Additional Notes:
This standard was proposed and managed by Shenyang Pump Research Institute. This standard was drafted by Shijiazhuang Pump Factory. The drafter of this standard was Zhang Chongen.
Maximum cross-sectional size 1
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