Summary: The article elaborated cast above all common flaw, next, the examination with respect to cast blemish and repair those who had development to discuss, have fair referenced value. Keyword: Cast blemish; Examination; Repair foreword foundry technology and other technology photograph are compared, be, more sophisticated technology. In casting production entirely, the factor that affects cast quality is very much, produce all sorts of types very easily cast blemish. Although cast produces limitation. But not, the law treats waste. Answer to undertake concrete analysis according to the particular case of cast, certain after the cast course that casts blemish is repaired, still can use. Blemish of cast of common flaw has 1 cast: Cold lie between, irrigate insufficient, stoma, stick arenaceous, clip arenaceous, sand holes, bilge arenaceous etc. 1) cold lie between and irrigate metal of insufficient liquid state to fill model capacity is insufficient, or fill model the condition is poorer, be in model antrum by cram before, metallic fluid stops flow, will make cast generation is irrigated insufficient or cold lie between blemish. When irrigating inadequacy, can make cast cannot win complete figure; Cold when lying between, although cast can win complete external form, but because put the juncture that has not complete confluence, the mechanical function of cast is damaged badly. Prevent to irrigate be not worth and cold lie between: Rise pouring temperature and pouring speed. 2) stomatic gas is not seasonable before case of metallic fluid bear transgression, the hole that makes inside cast kind blemish. Stomatic wall is smooth, bright or contain slight oxidation scene. After the generation in cast is stomatic, will reduce its to bear the weight of effectively area, and in the impact resistance that stress can be caused to center all round air hole and reduces cast and fatigue resistance. Air hole still can reduce the compact sex of cast, cause certain requirement to bear the cast of hydraulic experiment discards as useless. Additional, air hole also has undesirable effect to the corrosion resistance of cast and hear resistance. Prevent stomatic generation: Reduce metallic fluid to contain tolerance mediumly, increase the permeability of sand mold, and in model the top part of antrum is added vent one's anger rising head. 3) stick arenaceous cast apparently the arenaceous bead that conglutinate has to keep clear of hard is called stick arenaceous. Stick arenaceous affect cast exterior already, increase the workload that cast clears and cutting machines again, can affect the life of the machine even. For example casting tine surface has stick arenaceous when easy attaint, in the machine spare parts such as pump or engine if have,stick arenaceous, will affect the flow of the fluid such as fuel oil, gas, lube and cooling water, can be profaned and wear away whole machine. Prevent to stick arenaceous: Coal fines is joined in molding sand, and in casting mould surface besmear is brushed prevent stick arenaceous coating to wait. 4) the groove that places arenaceous to be formed in cast surface and scar blemish, using wet model cast large large slab kind when cast extremely easy generation. The place with arenaceous clip of the generation in cast is as conterminous as the surface on sand mold mostly touched place, model the effect that the surface on antrum suffers metallic fluid radiate to heat up, easy arch rises and warp, when the arenaceous layer of cock suffers metallic current to erode ceaselessly the likelihood ruptures broken, stay in former office or be taken other place. Of cast go up the surface is bigger, molding sand bulk expands bigger, form clip arenaceous tendentiousness is bigger also. 5) sand holes is worn in cast interior or exterior congest the hole of molding sand kind blemish. 6) bilge below the in metallic fluid pressure action when arenaceous is pouring, casting mould wall is mobile, cast is local and puffy formation blemish. Bilge to prevent arenaceous, should raise stiffness of sand mold intensity, sandbox, increase the force pressing case when closing case or close solid power, reduce appropriately pouring temperature, make the exterior in advance of metallic fluid writtens guarantee housing, be opposite in order to reduce metallic fluid the pressure of casting mould. The examination of 2 cast blemish is in whole in casting a process, must have quality inspection. Of cast the product quality inspection before examining to general component examines for intermediate technology and leave factory. Molding sand, core the quality inspection of arenaceous, about, core, molten iron is pouring of temperature detect and experiment before furnace, belong to those who assure cast quality intermediate technology examines. Cast quality inspection is to show according to the user requirement and design technology condition ask to wait for concerned regulation, examine with range estimation, span, appearance or other method whether does cast achieve eligible unit process of cargo bandling. Cast quality inspection should ask to undertake examining to allow with appearance of drawing of rough casting according to the accuracy class of cast and technology. Cast can divide by its quality it is 3 kinds: Qualification is tasted (accord with a technology to ask) ; Parts returned for repair (although have drawback, but via repairing correctional hind can achieve a technology to ask) ; Reject (cannot repair) . Cast quality inspection includes exterior quality, immanent quality and service mass. 1) visual quality of casting examines it is to point to cast surface state and the level that reach user requirement, include public errand of blemish of exterior surface roughness, surface, dimension, appearance and weight deviation to wait. Wait with observation or instrument commonly examine, commonly used method has fluorescence to examine, chromatic examine, kerosene soak examines and magnetic particle examines etc. 2) cast is immanent quality inspection it is to show the cast that cannot come out with macrography is in-house circumstance and the level that reach user requirement, include a few limitation of interior of organization of chemical composition, mechanical function, metallographic and consist in cast. General chemically analysis, metallographic examines, the method such as experiment of nondestructive flaw detection, material examines. Metallographic examines is a kind of method that use microscope has observing to cast fracture surface. Nondestructive examines is to point to do not damage cast, examine the method of its surface layer and in-house blemish. Basically have ray flaw detection, ultrasonic flaw detection, magnetic particle flaw detection, permeate flaw detection to wait. 3) cast service mass examines service mass examines is the function that shows cast can satisfy use requirement. For example, of cast can be waited for by treatment function, weldability. Of 3 cast blemish repair the cast blemish with commonly used to repair craft to have the following kinds: 1) solder filling uses gas welding or the solder of electric welding fills craft, it is cast blemish is the most commonly used kind in extensive grandson craft. Be like crackle, shrinkage cavity, cold lie between, sand holes cast blemish, can use rehabilitate of solder filling craft. To assure the repair quality of cast, when using solder filling technology, should notice the following: (1) to solder filling place clear before filling exercise of requirement solder, answer solder filling place to undertake admitting to clear really above all, compare concentrated position to blemish especially, should all Qing Dynasty shovels Yu Jing; Deep to comparing cast blemish, on the foundation of clear shovel, enlarge its even inside small outside big groove. To crackle blemish, should fill in solder before, in be apart from crackle the limitative aperture that the two restriction that carry 5mm~10mm place to get a diameter to be 6mm~10mm grain continues to develop, have solder filling operation again next. (2) a few righter but the solder of the cast with poorer be convenient to use fills measure solder fills is, kind the technique of local heating. As a result of local overheat, poorer to a few solderability cast, live fix the crackle defect with meeting new generation. For this, before solder fills must will wait for the cast that repair to undertake warm-up is handled, can adopt the method that solder of edge warm-up edge fills. 2) the metal irrigates plating the rehabilitate that this kind of technique applies to pair of cast intensity and function to affect not big cast drawback only. If cast is not the blemish such as the small shrinkage cavity of working place, conclusion, can adopt besmear plating a gold member film covers his the measure that rise, with achieving the goal that repair. 3) it is not important that adornment repairs to go up to cast the eyelet of place kind blemish, but the color according to cast, make up all sorts of be bored with child undertake decorating sexual fill. 4) set, the cavity that a place of strategic importance repairs to go up to cast, can machine aperture of corresponding a place of strategic importance, match head of a place of strategic importance next or use threaded coupling, besmear again join closely with water glass or colophony. 5) the fluid of metal of overheat of place infuse high temperature that of metallic fluid fill needs cast to repair above all, make cast blemish place fused, continue again next infuse metal fluid. Irrigate full hind, should undertake heat preservation cools, in order to prevent the casting stress with new generation, cause new cast defect. CNC MillingCNC Machining