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Influence factors of stamping die life have?

Hits: Date:2011-9-23 Font Size:14px 12px
Mould blowout reasons
1. Mould material is bad in the subsequent processing shatter easily
2. Heat treatment: quenching tempering process improper distortion
3. Mould grinding plane degree is not enough, produce bend deformation
3. Design process: mold insufficient strength, blade spacing is too close, die structure is unreasonable, template KuaiShu enough without legs pad
4. The line shears processing not: arrows, clearance wrong line shears, not clear Angle
5. Press the selection of equipment: punch tonnage, cutting force is not enough, so deep under the tonal template
6. Stripping not before production: no demagnetization processing, no output tip; Production in broken needle in a broken springs, and card material
7. Dropping material not: when a mold assembly no leak excrement, or roll plugging excrement, legs plugging excrement
8. Production consciousness: laminated stamping, positioning does not reach the designated position, didn't use blow air gun, a crack in the template continued to production
Die failure forms
Die failure forms of the main failure, failure to wear deformation and fracture failure and chew injury. Failure However, due to the different work conditions, punching process, the influence of different die life are various factors. Below dies in the design, manufacture and use, and other comprehensive analysis the influence factors of life die, and catch out the corresponding improvement measure.
1, press equipment
Press equipment (such as press) and accuracy of the influence of rigid die life is very important. Press equipment for the high precision, good rigidity, die life greatly improved. For example: silicon steel die materials for Crl2MoV complex, in the ordinary type presses use, average after grinding life for 1-30000 times, and the new precision presses, die use of the complex grinding life can reach 6 ~ 120000 times. Especially foot small gaps or no clearance dies, hard alloy die and precision die must choose high precision, rigid good press, otherwise, will reduce die life, serious still can damage is to provide.
2, mold design
(1) the precision mould steering mechanism. Accurate and reliable guide, to reduce wear of the mould work part, avoid convex, concave die chew injury has great influence, especially no clearance and small gaps punch die, composite modulus and multi-position into the mold is more effective. In order to improve the die life, must according to the nature and precision of parts process requirements, to choose the right form of leadership and determine the precision of the steering mechanism. Usually, the precision of the steering mechanism should be higher than the convex, concave die sought degrees with.
(2) mould (convex, concave die) of blade geometry parameters. The shape of the convex, concave die with clearance and fillet radius, not only for stamping has great influence, but also to die of wear and tear of life also affected. Such as mould fitting clearance of directly influence the blanking pieces and die life quality. Higher accuracy, appropriate chooses the smaller gap value; Otherwise, can be appropriately increased clearance, in order to improve die life.
3, stamping process
(1) stamping parts of raw materials.
In practical production because of the pressure parts, raw materials of tolerance, material thickness tolerance performance fluctuations, surface of poor quality (such as rust) or not clean (such as oil) and so on, can cause die working parts wear is intensified, easy to collapse bad consequences, such as the blade. Therefore, should pay attention to: (1) use as far as possible stamping technology of raw materials, to reduce the stamping good deformation force; (2) should be strict inspection before pressing the raw material of the brand, thickness and surface quality, etc, and will wipe clean raw materials shall, when necessary, cleared surface oxides and rust; (3) according to punching process and raw materials species and, when necessary, can arrange softening and surface treatment, and chose lubricants and lubrication process.
(2) arrangement and take edge.
No reasonable reciprocating feeding arrangement method and the too small a boundary value often causes mould dreadful or convex, concave die chew injury. Therefore, in considering raising material sentenced to use at the same time, must according to finish parts processing batch, the quality requirements and mold fitting clearance and rational selection of arrangement method and take boundary value, in order to improve die life.
4, mould material
Die material to the life of die is material influence species, chemical composition, the organizational structure, and the hardness and the metallurgical quality, etc ZhuGang the comprehensive reflection of cable. Different material die life, often different. For this to work, stamping parts materials make two basic requirements: (1) the use of material properties should have high hardness (58 to 64 HRC) and high strength and high wear resistance and toughness, enough heat treatment deformation small, has the certain hot hard; (2) technology has good performance. Die working parts processing manufacturing process normally is more complicated. Therefore it must be to all the processing technology has the adaptability, such as ductility, cutting machining, quenching, rigid, its quench-hardening ability, quenching cracking sensitivity and grinding process. Usually stamping according to the material properties, production batch, the accuracy etc, choose the excellent performance of mould material, and pay attention to its technology and economy.
5, thermal processing
Practice proves. The mould quality to mold the hot working performance and service life of great influence. From the analysis of the failure cause mould statistics, it is known that the improper because of heat treatment by mold failure "accident" about 40% above. Die working parts of quenching deformation and cracking, processes the use of early fracture, all of the thermal processing with touch with relevant.
(1), this is die forging process work parts manufacturing process is an important step. For high alloy steel mold, usually on the material such as distribution of carbide microstructure out technology requirements. In addition, still should strictly control the temperature range of forging, formulate correct heating standard, the correct forging force method, and after cold forging or slow in time. Annealing
(2) prepare heat treatment. Should inspect the mould work parts material and requirements of the different respectively by means of annealing, is fire or heat treatment process such as conditioning prepare to improve the organization, eliminate forging defects of blank, improve the processing manufaturability. High carbon steel alloy after heat treatment of preparation for the appropriate can eliminate mesh secondary cementite or chain carbide, make carbide spheroidizing, refinement, promote carbide uniformity of the distribution. This helps to ensure that quenching and tempering quality, improve die life.
(3) quenching and tempering. This is the key link of die &mould heat treatment. If quench heating cause overheating when, not only will it to make the work to cause major brittle, and in cooling easy to cause deformation and cracking, the serious influence die life. Die quenching heat should pay attention to prevent oxidation and special decarburization shall be strictly controlled, heat treatment process specifications, in conditions allow, can use the vacuum heat treatment. After quenching shall promptly, and according to the technical requirements for tempering by different tempering process.
(4) away stress annealing. Die working at the early parts should be back after stress relieving treatment, with purpose is to remove the internal stress caused by rough machining, lest produce big deformation quenching call and crack. For high accuracy of mold, in grinding or electric processing need to pass away after the tempering treatment, stress to steady precision mould, improve the service life.
6, processing surface quality
Die working parts and the surface quality of the quality of the wear resistance, resistance to mould fracture and the ability to stick with ability has a very close relationship, directly affect the service life of the die. Especially the surface roughness to die life is affected if the surface roughness value is too big, in the work can produce the stress concentration in the peak phenomenon, and the valley of easy to crack, between the durability influence, stamping, will also affect the surface, the corrosion resistance of directly affect the service life of die and precision, therefore, we should pay attention to the following items:
(1) die working parts processing process must prevent grinding burns parts surface phenomenon, should strictly control grinding process conditions and process methods (such as hardness, grain size, grinding coolant, feeding parameters);
(2) the processing process should prevent die working parts surface with knife scar. Sandwich, crack, scars and macro defects impact.