上海理工大学金工实习答案doc.docx

1、上海理工大学金工实习答案doc上海理工大学金工实习答案Chapter 1 heat treatmentNon title (Title):For over eutectoid steels, the higher the carbon content, the higher the quenching temperatureQuenching and tempering of heat treatment process called quenching and tempering, Quenched and tempered parts can obtain strength, toughn

2、ess, plasticity are better comprehensive mechanical propertiesSpring quenching treatment generally use high temperature tempering, because the high temperature tempering, the highest elastic limitBrinell hardness is suitable for measuring materials of high hardness, such as hardened steel, etcChoice

3、 question：Manufacturing connecting rod, transmission shaft Generally used (medium carbon steel)The heat treatment and quenching and tempering process is(quenching and tempering at high temperature)Spring steel parts are used after quenching (medium temperature tempering)Oxidation decarburization Ile

4、al treatment is selected(controlled atmosphere heat treatment furnace)In order to change the speed gear Alloy steel gear(carburizing, quenching, low temperature tempering)The steel with relatively good machinability is (high carbon steel)Slender shaft When quenching should be (verticaldownward)The h

5、eating range of gas carburizing is (900930)Carbon steel quenching The tissue is transformed into(martensite)Rockwell hardness of 45, the expression for the 45HRCFill in the blanks:(annealing) furnace cooling (air cooling normalizing) (quenching) rapid quench cooling (quenching tempering) (heat treat

6、ment) heating, cooling (general) internal organization (metal material) hardness, strength, tensile strength, type of (most commonly used) carburizing, nitriding, chromizingThe second chapter is casting practice reportTo determine the problem of error:In manual molding, the sand is pressed as tightl

7、y as possible, and the strength is highThe important working face, stress surface or main processing surface of the casting shall be facing upwards when pouringChoice questionThe function of parting sand is to analyze the molding sand and the molding sand smoothlyThe main reason for casting sand is

8、that the pouring temperature is too high and the refractory of molding material is not obviousIn order to improve the fluidity of molten metal, the increase of pouring temperature should be adoptedThe action of adding pulverized coal to sand is to prevent sticking sand andThe important processing su

9、rface of the casting, as far as possible in the shape of the casting (below)Investment casting is suitable for manufacturing (shape, complex casting)The role of the riser (feeding and exhaust)The melting temperature of molten aluminum is (800)Because of metal The shrinkage is about (1. 5%)What is su

10、itable for casting is (lathe tailstock and slide plate handwheel)CompletionSpecial (casting) (sand composition) of sand and binder and additives ( is the sand sand body) good permeability, suitable temperature, high temperature, certain concessions, sufficient durability (hand molding) the whole mol

11、d, parting, dredging, floating block, three tank (three box styling) two, three (typical casting) outside the gate, gate, gate mode (cast iron crucible) (castings) sand blasting, water cleaning, water cleaning (Foundry) investment casting, pressure casting, centrifugal casting, ceramic cast (casting

12、 speed positive)Short Answer Questions1. What are the characteristics of foundry production?Answer: 1. casting can obtain complex shape casting; 2. casting size and weight can be big or small; 3., casting cost is low2.what is the parting surface in Casting modeling? What are the factors that should

13、be taken into consideration in the selection of parting planes?Answer: parting surface refers to the sand interface, generally choose the largest secti on of the casti ng is the parti ng surface, but also consider convenient molding, moldWhy should I brush the water on the sand pattern around the 3.

14、 moulds? What points should be noticed in mold lifting?Answer: increase the strength of this part of molding sand, prevent mould from damaging sand mould Note: 1. water should be a brush and brush; 2. die, die to die and needle position center of gravity vertical overlap4. what are the functions of

15、the gating system?Answer: 1，the metal liquid can be continuous, smooth, uniform into the cavity,Avoid punching mould, cavity and core; 2. prevent slag, sand and other magazines into the cavity; 3. adjust the solidification sequence of each part of the castingWhat is the role of the 5. riser? Where i

16、s the general riser located?Answer: 1. exhaust cavity gas; 2. to slag; 3. feeding; 4. observation; 5. guarantee the quality of casting The position is usually located on the thickest wall of the casting and at the final setting.6. what are the characteristics of metal mould casting in special castin

17、g?Answer: 1. good mechanical performanee, long service life; 2. high precision, smooth surface and good thermal conductivity of metal type, cooling speed; 3. the lack of air permeability and deformability, heat resistance than sand; 4. complex castings crack; 5. is not suitable for high melting poin

18、t metal casting; 6. processing complex, high cost9. , pouring temperature is too high or too low will have any adverse effects?Answer: too low: metal liquid fluidity is poor, gate size is too small, metal liquid filling speed is too slow, mold ventilation, poor exhaust, parting surface running fire,

19、 make the upper box casting insufficientExcessive: produce sticky sand, shrink hole, sand, short pouring, cold separation, slag eyeThe third chapter is forgingYes no questions wrongThe cooling method after forging has little effect on the quality of the forgingsThere is no need for any further proce

20、ssing of the forgingsDie forging is to place the heated metal germ into it MethodoChoice question45 steel starts with forging temperature and final forging temperature (1150、800)Grain of forging embryo This defect is often referred toas (overheating)The forge heating furnace (high temperature box re

21、sistance furnace) used in engineering trainingThe following metal can be used for forging (45 steel)If you want to process 3 pieces 45 (free forging)If you want to process 3000 pieces of 40rMo steel (dieforging)In order to avoid upsetting (less than 2.5)For example, during the process of forging hea

22、ting, the correct treatment method is scrapCompletion(forging metal forging, forging press) (forging) initial forging temperature, forging temperature (forging) manual, machine, manual and machine (forging) stretching, punching, cutting, bending (forging can be divided into membranes, model)The four

23、th chapter welding practice reportYes no questions wrongIn welding, the faster the electrode moves, the betterArgon arc welding is divided into two kinds of argon arc welding and non melting argon arc weldingWhen welding, the welding workpiece thickness on the deformation of the workpiece has little

24、 effectChoice questionThe diameter is 3, 2mm (b)In manual arc welding, the length of the normal arc (equal to the diameter of the electrode)Eye can not (night eye pain and photophobia)Gas, oxygen and acetylene (3500)Use oxygen, acetylene (preheating, combustion, slagblowing)The following 3 welding m

25、ethods Fusion welding (argon arcwelding)When soldering, the weldment and the solder (the weldment does not melt and the brazed piece melts)Welded stainless steel (argon arc welding)National standards Oxygen bottle (sky blue)National standards Acetylene (white)Completion(electric welder no-load volta

26、ge 6070 AC, DC) 40、90, 2030V (electrode coating) ore, iron alloy, chemical composition, organic matter, improve the welding process of welding, protection, good metallurgical chemistry (welding) welding, brazing, pressure ( the main weld butt, T), fillet, lap(Weld Internal) welding crack, weld poros

27、ity, slag inclusion, unweld (SMAW) percussion, frictionShort Answer Questions10. what are the protective measures during welding operations?Answer: foot cover, overalls, masks, gloves, work capThe fifth chapter is turningYes no questions wrongWhen the vehicle is outside the circle, the utility model

28、 can also be driven by a screw rod to realize a longitudinal automatic cutterIn the rough lathe, the lathe tool should take the big rake angleThe car outside screw tap, die inside threadChoice questionTurning slender shaft (bulging)Turning tool at cross section (gradually decreasing)Transmit power i

29、n the window headstock (friction clutch)Hand it on a lathe (a workpiece with a high precision anda small amount of production)A lathe tool with a smaller rake angle (Rough car)Take the back angle of the lathe tool (positive)Foot measurement has tolerance requirements (verniercaliper)Finishing time C

30、onsider (cutting depth)Surface finish quality and After (conditioning, heattreatment)Removal of turning process Must use (special hook)Completion (C616) spindle box, gear box, tailstock, knife, feed box, slide board (general turning) 710, 1. 60. 8 ( lathe main) turningfacing grooving and cutting, ch

31、amfering, car vertebrae, threading, knurling, drilling, car (installation steps () tool axis in your practice) 1980 rpm, 45 rpm, 12 (three jaw chuck) shape, irregular shape (by cutting) 90 degrees 75 degrees turning, turning, cutting knife (usually turning cone) to rotate a small carriage, offset th

32、e tailstock profiling method, (turning forming surface) hands control method, forming blade pitch (replacement)Short Answer Questions1.write down the type of lathe you are working on and explain what the symbols representC616 C- lathe type 6- horizontal lathe group code 16- the maximum turning diameter of machined workpiece 1