Urgent! ! ! Qinhuangdao tobacco machinery co., ltd. written examination questions.

(ABS

plastic

)

18

Selection of spark plug for internal combustion engine

(

aluminium oxide

)

Ceramic materials.

19

Chemical pipeline pumps and other components that require corrosion resistance and aging resistance can be selected.

(

polytetrafluoroethylene

)

Engineering plastics.

20

These three solid materials refer to

(

metal material

ceramic material

polymer material

)

2 1

The most traditional and accurate method to determine the chemical composition of metal materials is

(

Chemical analysis method

)

22

Determine the hardness of metal materials with coarse grains or constituent phases, such as gray cast iron and bearing alloys, and anneal and normalize steel parts.

Fire and hardness after tempering are often used.

(

Brinell hardness

)

hardness-testing device

23

Machine tools are usually used.

(

gray pig iron

)

24

There are three isothermal transition lines in the iron-carbon phase diagram.

(

Peritectic transformation

* * * Transformation analysis

* * * Crystal transformation

)

25

The hardening ability of steel depends on

(

Carbon content of steel

)

26

The temperature of quenching oil tank is generally controlled at

(80

℃

)

Below.

27

Beryllium bronze can be used.

(

Solution aging

)

Strengthen.

28

In order to avoid and reduce the oxidation and deoxidation of steel parts during heat treatment, it is best to use

(

vacuum furnace

)

29

High-speed steel straight shank twist drill adopts

(

Oxygen sulfur carbon nitrogen boron penetration

)

Chemical heat treatment has the highest durability.

30

65Mn

The common methods of strengthening and toughening steel spring parts are as follows

(

isothermal quenching

)

3 1

Finally, the surface of machine tool guide rail is quenched.

(

Ultrasonic quenching

)

Heat treatment.

32

Gray cast iron drawing die must be carried out.

(

Cr-Nb co-infiltration

)

Strengthening and toughening treatment can significantly improve the service life of the die.

33

When ductile iron is used to make drawing dies, it needs to be normalized and tempered.

(

Nitrogen-carbon permeation

)

Chemical heat treatment.

34

When machining excircles and holes on lathes, chaotic ripples appear because

(

Large axial movement of lathe spindle

)

35

Which of the following is used when machining workpieces?

(

A flat workpiece that is not easy to clamp.

)

The forward milling method is more suitable.

36

Which factor is most likely to cause surface burn of workpiece during cylindrical grinding?

(

Grinding wheel is too hard

)

37

(

Partial interchange assembly method

)

The assembly method should solve the assembly size according to the probability method.

38

In order to ensure the coaxiality accuracy of the center height of the machine tool spindle and the center height of the tailstock,

Which assembly method should I choose?

(

fixed

assembly method

)

39

What kind of phenomenon occurs when the machine tool spindle is running indicates that the working clearance of the rolling bearing supported by it is too small: spindle support.

The temperature of the bearing part is obviously increased.

40

General cutting speed

(m/min)

Indicates the speed used by WEDM.

(mm2/min)

table

Show.

4 1

The minimum wall thickness of castings produced by different materials and different casting methods is different. Gray cast iron is cast in sand mold.

Pieces, can get the minimum wall thickness is

(3 mm

)

Forty two.

If a closed casting system is used,

Gate area,

Door area,

The proportion of gate area should be

( 1. 15: 1. 1: 1)

43

When the minimum wall thickness of aluminum alloy is obtained

0.6-0.8 mm

When should it be adopted?

(

Die-cast

)

Casting.

Forty-four

Different working modes of pressure make the internal force of metal different.

Therefore, processed metal will be produced.

(

same

)

Ductility

45

The specific gravity of forging is not the specific gravity of the workpiece before and after deformation.

(

ratio by volume

)

To show.

46

Free forging can be divided into manual forging and machine forging. At present, mechanical forging is the most widely used, which leads to the shape of forgings.

And size are mainly determined by

(

Technical level of operators

)

Decide.

47

Most of the raw materials used in the stamping process belong to

(

plastic

)

Good metal materials, such as ordinary low carbon steel, copper and aluminum alloy.

Jin et al.

48

Three welding methods refer to

(

fusion welding

braze welding

Push welding

)

Forty nine

In welding production

(

electro-weld

)

Welding method is dominant.

50

The welding arc consists of cathode zone, anode zone and cathode zone.

(

Arc column area

)

Composition.

5 1

The welding arc temperature can be reached.

(5,000-30,000)

Fifty two

During the welding process,

each

five

There is one every minute.

2

Time for replacing covered electrode and removing slag,

The continuous load rate of power supply is

(60%)

55

Automobile body is widely used.

(

Cathode electrophoresis

)

Painting method.