Guangxi ChangCheng Mechanical Limited by Share Ltd high manganese steel large castings enterprise standard
1. subject content and scope of application
The standard sand casting high manganese steel parts refer to 750*1060, 900*1200, 1500*2100 jaw crusher jaw crusher, and 900, 1200, 1750, 2200 cone crusher crushing wall, rolling mortar wall and other castings, in order to ensure the quality of the product in order to produce and control the main processes in order in the actual production process. Stability, quality inspection throughout the whole process of production. Such as material selection control; smelting composition control; casting heat treatment requirements; casting correction; casting surface quality; casting defect repair, hardness test; sample inspection and analysis of casting finished products, product label, production date and so on, specially formulated this standard.
2. reference standard
People's Republic of China national standard, high manganese steel castings GB T5680 2010
3. production brand
High manganese steel chromium 2, ZGMn13Cr13Cr2 and national standard ZGMn13-4
4. Chemical composition
Regulation of smelting control symbol table 1
Brand name | Chemical composition % | |||||
C | Mn | Si | Cr | S=< | P=< | |
ZGMn13Cr2 | 1.2-1.38 | 12.5-14 | 0.30-0.70 | 1.50-2.50 | 0.03 | 0.06 |
5. furnace control
(1) the content of carbon steel P is less than 0.035%, and the content of P for returning manganese steel is less than 0.07%, and the P content of manganese steel rail is less than 0.065%.
(2) a ferromanganese alloy is required to use 75 fiercely.
(3) match pig iron: cast 15, code Z15, level 1.
6. The analysis and adjustment of the composition before the furnace
(1) smelting is strictly regulated according to composition, sampling and testing before each furnace, reasonable adjustment of composition and control of Mn/C ratio.
(2) sampling and analyzing chemical composition after the furnace and strictly recording the inspection results.
7. Heat treatment of castings
(1) the casting holding time is controlled according to the size of the casting and the degree of re blasting. Reduce the shrinkage stress of the castings.
(2) the casting method requires uniform heating.
(3) strictly enforce the heating curve of high manganese steel, and the temperature rise curve must be kept on a date basis.
(4) the casting time of the casting is less than 1 minutes.
(5) the water temperature is not more than 30 degrees centigrade when the temperature is highest.
(6) the temperature of the castings after water is less than 70 degrees centigrade.
8. Casting correction
(1) the basic size correction of castings is shown in Table 2 and table 3.
Tolerance table of straightness and flatness 2
Castings | >630-1000 | >1000-1600 | >1600-2500 |
Dimensional tolerance value | 4 | 5 | 6 |
Roundness tolerance table 3
Castings | >400-630 | >630-1000 | >1000-1900 |
Dimensional tolerance value | 4 | 5 | 7 |
(2) tolerance of hole and groove and tolerance of assembly hole distance are shown in Table 4 and table 5.
Size tolerance table for holes and grooves 4
Aperture and slot | >25-40 | >40-63 | >63-100 |
Dimensional tolerance value | +3 | +3.5 -0 | +4 -0 |
Assembly hole distance to ground dimension tolerance table 5
Assembly hole distance | >250-400 | >400-1000 | >1000-1600 |
Dimensional tolerance value | +-3 | +-4 | +-4.5 |
9. surface quality of castings
(1) the surface quality of the castings should conform to the technical requirements of the drawings, smooth and clean. In particular, the assembly surface must be polished and leveled, with no bumps and sharp outlines.
(2) clear the gate, burr, sand and so on. Riser, the residual amount of gate cutting should meet the requirements of the supplier and the buyer.
(3) castings are not allowed to be affected by cracks and holes. Casting defects such as slag inclusion.
10. defect repair of castings
(1) small defects in welding defects are allowed for casting defects. The defects should be cleaned up before welding and the technical requirements of castings can be achieved after welding.
(2) the welding repair of the important parts should be grinded clean, with stainless steel electrode, welding repair according to the technical requirements of manganese steel welding, the welding temperature should not exceed 260 degrees Celsius.
11. hardness test of castings
(1) the hardness of castings must be checked for every batch of products produced on the same day or in the same furnace heat treatment.
(2) the hardness is controlled within the range of HB180-245.
(3) hardness test method, in the same product, polished a flat, hit five hardness points, take the average hardness value.
12. Sampling inspection of the components of finished products
(1) the products must be analyzed by sampling and analysis.
(2) sampling method, we can know the gate of the casting and the sampling on the riser. The analysis results are in three copies (from storage, plant and Technology Department).