Some model lamina of 2 class guider is out of shape and crackle analyses engine

The Results Show That The Non-unibormity Of Engine Temperature Fields And The Partial High Temperature Lead To Overheat Of The Nozzle Vanes And Result In Deformation And Cracks.

Thermal Stress1 of 　 of Superalloy of 　 of Crack of 　 of Deformation of Keywords 　 Overheat 　 summarizes some model engine flies in the factory two rise and fall (the examination after making an appointment with 3h) , discover engine to the edge taking energy of life of lamina of 2 class guider is out of shape and appear crackle, discover 14 engine appear in succession again later similar breakdown. According to statistic, the position of breakdown lamina all is centered in 1 ＃ , 5 ＃ and on 31 ＃ , be out of shape with the lamina of 5 ＃ position among them most serious, occurrence number is maximum, some deflection already amounted to 10mm above, after blade is out of shape, bend apparently, cause its small axis is taken out from inside tying annulus hole, blade tilts backward and photograph of lamina of 2 class turbine is ground. The 5 ＃ blade that the article takes P7830141 date engine (of this lamina cast furnace date to undertake managing changing an analysis for 82D1324) , so that find out blade,be out of shape and produce the account of crackle. 2 tests result 2.

Exterior of lamina of 5 ＃ breakdown is like 　 of 1 visual examination the graph is shown 1 times. There is to grow on face of basin of leaf of the edge that take energy of life for 13.

Of 96mm transverse advocate crackle, be apart from small installing plate for 21.

8mm, be in advocate crackle lower part 10.

3mm place still has 4.

The small crackle with long 2mm, in advocate two side have flaw distinct lines, this kind of furrow arrives from the edge that take energy of life by the side of exhaust by wide narrow, and gradually die, furrow area shows hoar. Be in advocate of crackle around, xiang Xie carries blade on the back to direction bends and be out of shape badly. 2.

2 material check some character model engine lamina of 2 class guider with K403 nickel radical casts casting of essence of high temperature alloy and into, the 4 ＃ position from breakdown lamina (graph 1) is cut take sample, chemical composition analysis expresses place to show as follows as a result. Graph 5 ＃ of 1 　 breakdown lamina (foliaceous basin face) Fig of exterior form appearance.

　 of Vane (face) of ＃ of 1 　 Appearance Of The Failed 5 by the watch 1 knowable, ask than technical condition except B element slightly low outside, other element all accords with technical requirement. Express composition of chemistry of lamina of 5 ＃ breakdown to analyse element of Blade of ＃ of Chemical Composition Of The Failed 5 of 　 of result Table 1, %CSiSPCrWMoAlTiCoB breakdown 0.

16 ＜ 0.

5 ＜ 0.

01 ＜ 0.

0210.

355.

274.

315.

472.

605.

160.

008 technologies condition 0.

11 ～ 0.

18 ≤ 0.

5 ≤ 0.

01 ≤ 0.

0210 ～ 124.

8 ～ 5.

53.

8 ～ 4.

55.

3 ～ 5.

92.

3 ～ 2.

94.

5 ～ 6.

00.

01 ～ 0.

032.

3 metallographic observation is in advocate crackle place is cut take metallographic sample, face of edge leaf basin is ground make sample, classics after corroding, observe below metallographic microscope, if pursue 2 with the graph 3 are shown. Can see apparently, the deepness that blade makes an appointment with 10mm into gas edge (quite the 3/4) with long crackle appears anti-corrosive phenomenon, brilliant granuality shows do not come out. In crackle initiative area and patulous area all did not discover metallurgy flaw. Crackle is patulous direction is as perpendicular as the edge that take energy of life, crackle appearance is sinuate, belong to edge brilliant to rupture. Graph 2 advocate crackle form appearance reachs his to organize 2 × Fig.

2 　 Morphology Of Main Crack In The Failed Vane pursues 3 graphs the enlarge of 2 9.

2 × Fig.

3 　 Higher Magnification Photograph Showing The Same Crack From Above Figure2.

4 report lens observes in foliaceous body different position is cut take metallographic sample, 2 carbolic answer, with transmission report lens observation breakdown lamina differs the microstructure of place. Above all, edge leaf body is fore-and-aft be in respectively 1 ＃ , 2 ＃ and 3 ＃ position (detailed sees graph 1) sampling, if result of electric lens observation pursues 4. By the graph 4 visible, 1 ＃ position stands by small installing plate outside, be apart from advocate crackle 22.

3mm; 2 ＃ position is stood by advocate the furrow place below crackle; 3 ＃ position stands by big installing plate to be in, be apart from advocate crackle 80mm. Knowable, photograph of ′ of γ of 1 ＃ position and carbide are basic and normal, but γ ′ photograph is brought up somewhat; Photograph of ′ of γ of 2 ＃ position is all and deliquescent, when foliaceous body is cool, new separate out 2 petty γ ′ photographs, the temperature that proves the place already exceeded the temperature that photograph of ′ of K403 alloy γ dissolves completely; Photograph of ′ of γ of 3 ＃ position and carbide are normal, because stand by big installing plate here, temperature is inferior. Graph the organization of Xie Shenzong of lamina of 4 edges breakdown to different position 5000 × Fig.

　 of 4 　 Micrographs Of The Failed Vane In Its Different Positions Along A Lingitudinal Direction next, along advocate crackle is patulous direction (foliaceous body is transverse) the electric lens organization that divides a place to observe breakdown lamina, the limits of every place is about 1.

75mm, the edge that observes the position is apart from crackle is 0.

If 8mm(pursues 3 in arrowhead place shows) , observe if pursue,as a result 5 are shown. By the graph 5 can see, come from the 1st place of the brim that take energy of life the 4th place, γ ′ photograph is completely deliquescent, after air is cold new separate out 2 petty γ ′ photographs, return rudimental part carbide, visible, the γ ′ photograph that the real work temperature of these place already exceeded K403 alloy dissolves completely temperature; Organize form appearance to the 7th place from the 5th place basic and identical, γ ′ photograph dissolves for the most part, and separate out 2 petty γ ′ photographs, remain γ ′ photograph mixes one fraction carbide, the real work temperature of these place is quite high also, had been close to the temperature that γ ′ photograph dissolves completely; The 8th have to the 9th place a few γ ′ Xiang Rong is solved, accompanying separate out of γ ′ photograph 2 times. (4 place of 1)1 ～ 　 of 　 of 　 of 　 　 　 (7 place of 2)5 ～ 　 of 　 of 　 of 　 　 　 (9 place of 3)8 ～ pursue the organization of Xie Shenheng of edge of 5 breakdown lamina to different position 5000 × Fig.

5 　 Micrographs Of The Failed Vane In Its Different Positions Along A Transverse Direction2.

5 imitating test are the temperature that photograph of ′ of γ of affirmatory K403 alloy dissolves completely, did two imitating test especially: (1) is used to K403 alloy heat differently temperature, watch pattern of γ ′ photograph with method of lens of metallographic, report, measures photograph of ′ of K403 alloy γ is completely deliquescently temperature is 1210 ℃ , if pursue,6 are shown. Graph lens of the report after 1210 ℃ heat organizes alloy of 6 　 K403 5000 × Fig.

　 of 　 of ℃ of 6 　 Electron Micrograph Of K403 Alloy Heated At 1210 (2) is in to K403 alloy same heat temperature (1250 ℃ ) below, use different heat preservation time, watch the pattern of γ ′ photograph with method of lens of metallographic, report, measure so that K403 alloy is below 1250 ℃ , heat 3min enough makes γ ′ photograph dissolves completely, if pursue,7 are shown. Graph the electric lens after 1250 ℃ 3min organizes alloy of 7 　 K403 6000 × Fig.

For 3min2 of ℃ of 7 　 Electron Micrograph Of K403 Alloyheated At 1210.

If pursue,6 fracture surface analyse macroscopical fracture surface 8. By the graph 8 visible, crackle result takes gas side, crackle is patulous direction and photograph of the edge that take energy of life are perpendicular; Fracture surface is rough, rugged; Crackle source area (horny R is in the Bian Yuan that take energy of life) column brilliant direction is not clear, grain is petty, organization of occurrence Chu Rong concerns this likelihood and surface layer of the edge that take energy of life. Whole fracture surface belongs to edge brilliant to rupture. Carbon 2 answer model observe with transmission report lens, brilliant of edge of area of fracture surface source ruptures form appearance is shown 9 times like the graph. Graph 5 ＃ of 8 　 the macroscopical fracture surface of breakdown lamina 6 × Fig.

Vane of ＃ of 8 　 Macro-fracture Of The Failed 5 pursues lamina of 5 ＃ breakdown enters 9 　 appearance of form of gas edge fracture surface 5000 × Fig.

Vane3 of ＃ of 9 　 Fracture Morphology Of Leading Edge Of The Failed 5 discusses 3.

The working temperature of lamina of guider of 1 2 class material of lamina of 2 class guider for K403 nickel radical casts high temperature alloy, its work normally temperature is controlled for 950 ℃ . The experiment proves: Photograph of ′ of γ of place of lines of the boundary that take energy of life is completely deliquescent, metallographic organization produces change, bring about alloy function to drop. Imitating test measures the temperature with a completely deliquescent photograph of ′ of K403 alloy γ to be 1210 ℃ , it is thus clear that lamina of 2 class guider works actually temperature Yuan Chao gives regular job temperature, be as high as 1200 ℃ above. Below so high job temperature, the ′ of γ of main aggrandizement photograph of alloy is in a few minutes in can dissolve completely, alloy produces overheat or burn too, intensity and plasticity drop quickly. Russia data covers before, Ж С - 6 К nickel base when casting high temperature alloy to compare 900 ℃ in the long-term strength when 1030 ℃ , should drop 1/3; Intensity of high temperature instantaneous should drop when 900 ℃ are compared when 1100 ℃ 2/3. Accordingly overheating overheat or be being burned too is to bring about lamina of 2 class guider to be out of shape the dominant element with crackle. 3.

The thermal stress of lamina of guider of 2 2 class works normally in engine below condition, lamina of 2 class guider bears lesser oscillatory stress and thermal stress. When engine temperature field is inhomogenous, blade takes gas side local district bears the high temperature of 1200 ℃ above, be heated place warms up quickly, the heat of foliaceous body expands, heat up as a result of foliaceous experience on one hand inhomogenous, interiorly is restrained, on the other hand outer ministry is restrained with what combine annulus by casing. Below the action of double sanction, heat expands suffocate suffocate, produce huge thermal stress in foliaceous body interior then, succumb when what the level of this kind of thermal stress exceeds material when intensity, foliaceous body produces plasticity to be out of shape; When exceeding intensity limit, foliaceous body happens rupture. Visible, of lamina of 2 class guider be out of shape and the result that crackle is thermal stress action, and this kind brings about blade to be out of shape the thermal stress with craze, basically originate the overheating effect that blade takes gas side. 4 conclusion 　 (the material of lamina of 2 class guider accords with 1) character the requirement of technical condition; All did not discover metallurgy flaw in the initiative place of crackle and patulous area; Of blade be out of shape and crackle and material have nothing to do character. (Field of 2) engine temperature is inhomogenous, in fixed place (1 ＃ , 5 ＃ , 31 ＃ place) appear area of local high temperature, its are highest heat temperature is more than 1200 ℃ , cause lamina of 2 class guider to enter gas to the edge produces overheat or be burned too, cause blade to be out of shape with crackle. 5 proposals are designed and use a department from system of structure, combustion, use safeguard, debug wait for each respect, prove the cause with engine intensity inhomogenous field, adopt correct measure accordingly. CNC Milling CNC Machining