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起止时间:2021-04-26到2021-08-30
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1 Weldabitliy and Testing 1
1、 With carbon equivalent ( ), the steel has a low tendency to harden and cold cracking?
A:less than 0.40%
B:less than 0.50%
C:less than 0.60%
D:less than 0.80%
答案: less than 0.40%
2、 ( ) is not a factor that affects weldability.
A:chemical composition
B:Welding process
C:joint type
D:operation skill
答案: operation skill
3、 Maximum crack distance has been used to allow more accurate determination of the cracking ( ) range.
A:size
B: temperature
C:toughness
D:strength
答案: temperature
4、 The calculation formula of carbon equivalent of the IWS considers the influence of () on weldability.
A:diffusion hydrogen
B:welding process
C:welding structure
D:chemical composition
答案: diffusion hydrogen;
welding process;
welding structure
2 Weldability of Carbon and Low-alloyed Steels 1
1、 The weldability of high-carbon steel is worse than that of low-carbon steel because high-carbon steel is with ().
A:higher carbon content
B:higher toughness
C:higher sulphur content
D:lower melting point
答案: higher carbon content
2、 Normally, because of auto-tempering, the postweld microstructure of QTLA steel is ().
A:tempered martensite
B:upper bainite
C:high carbon martensite
D:ledeburite
答案: tempered martensite
3、 HTLA steels are susceptible to reheat cracking because they are with a lot of ().
A:carbides
B:hydrogen
C:sulphur
D:manganese
答案: carbides
4、 If the carbon content of a type of steel is 0.1%, this steel is a kind of ().
A:low-carbon steel
B:medium-carbon steel
C:high-carbon steel
D:HTLA steel
答案: low-carbon steel
5、 QTLA steel is not susceptible to solidification cracking because it is with ().
A:low carbon content
B:low impurity content
C:low manganese content
D:low nickel content
答案: low carbon content;
low impurity content
6、 For HTLA steels, chromium is able to ().
A:increase hardeness of HTLA steels
B:decrease toughness of HTLA steels
C:decrease hardeness of HTLA steels
D:increase toughness of HTLA steels
答案: increase hardeness of HTLA steels;
decrease toughness of HTLA steels
7、 Auto-tempering occurs after welding when ().
A:carbon content of weld is low
B:cooling rate is slow
C:peak temperature is high
D:Ms is high
答案: carbon content of weld is low;
cooling rate is slow
8、 When you weld HTLA steels, you’d better to take advantage of auto-tempering.
A:正确
B:错误
答案: 错误
9、 Before designing welding procedure, we’d better to analyze the weldability of the workpiece.
A:正确
B:错误
答案: 正确
10、 To remedy the underbead cracking, we need to reduce cooling rate when we weld oil engine connecting rod.
A:正确
B:错误
答案: 正确
3 Weldability of Stainless Steels 1
1、 No preheating is recommended during wielding of duplex due to ()
A:coarse grain
B:deformation
C:the formation of sigma phase
D:the formation of ferrite phase
答案: the formation of sigma phase
2、 During welding of duplex steels, stay on the duplex road is very important, too slow cooling might lead to ( )
A:high austenite
B:high ferrite
C:formation of sigma phase
D:cracking
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