第一章 单元测试
1、单选题：
With carbon equivalent ( ), the steel has a low tendency to harden and cold cracking?
选项：
A:less than 0.50%
B:less than 0.80%
C:less than 0.60%
D:less than 0.40%
答案: 【less than 0.40%】
2、单选题：
( ) is not a factor that affects weldability.
选项：
A:operation skill
B:chemical composition
C:joint type
D:Welding process
答案: 【operation skill】
3、多选题：
The calculation formula of carbon equivalent of the IWS considers the influence of () on weldability.
选项：
A:chemical composition
B:diffusion hydrogen
C:welding process
D:welding structure 
答案: 【diffusion hydrogen;welding process;welding structure 】
4、单选题：
Maximum crack distance has been used to allow more accurate determination of the cracking ( ) range.
选项：
A:strength
B:toughness
C:size
D:temperature
答案: 【temperature】
5、多选题：
Weldability is not easily quantified, and can depend on a variety of factors, including ( ).
选项：
A:operator and welder
B:physical specifics of the joint
C:welded structure
D:welding method
答案: 【physical specifics of the joint;welded structure;welding method】
第二章 单元测试
1、单选题：
The weldability of high-carbon steel is worse than that of low-carbon steel because high-carbon steel is with ( ).
选项：
A:higher carbon content
B:lower melting point
C:higher sulphur content
D:higher toughness
答案: 【higher carbon content】
2、单选题：
Normally, because of auto-tempering, the postweld microstructure of QTLA steel is ( ).
选项：
A:high carbon martensite
B:tempered martensite
C:ledeburite
D:upper bainite
答案: 【tempered martensite】
3、多选题：
QTLA steel is not susceptible to solidification cracking because it is with ( ).
选项：
A:low impurity content
B:low carbon content
C:low manganese content
D:low nickel content
答案: 【low impurity content;low carbon content】
4、多选题：
For HTLA steels, chromium is able to ( ).
选项：
A:decrease toughness of HTLA steels
B:increase toughness of HTLA steels
C:increase hardeness of HTLA steels
D:decrease hardeness of HTLA steels
答案: 【decrease toughness of HTLA steels;increase hardeness of HTLA steels】
5、判断题：
When you weld HTLA steels, you’d better to take advantage of auto-tempering.
选项：
A:对
B:错
答案: 【错】
6、多选题：
Auto-tempering occurs after welding when ( ).
选项：
A:peak temperature is high
B:Ms is high
C:carbon content of weld is low
D:cooling rate is slow
答案: 【carbon content of weld is low;cooling rate is slow】
7、判断题：
Before designing welding procedure, we’d better to analyze the weldability of the workpiece.
选项：
A:对
B:错
答案: 【对】
8、判断题：
To remedy the underbead cracking, we need to reduce cooling rate when we weld oil engine connecting rod.
选项：
A:错
B:对
答案: 【对】
9、单选题：
If the carbon content of a type of steel is 0.1%, this steel is a kind of ( ).
选项：
A:medium-carbon steel
B:HTLA steel
C:high-carbon steel
D:low-carbon steel
答案: 【low-carbon steel】
第三章 单元测试
1、判断题：
Weld metal of austenitic stainless steels is susceptible to weld decay.
选项：
A:对
B:错
答案:
2、判断题：
PWHT would be helpful to prevent the formation of weld decay in austenitic stainless steels.
选项：
A:对
B:错
答案:
3、判断题：
Adjusting welding sequence might be helpful to prevent the formation of knife-line attack in austenitic stainless steels.
选项：
A:错
B:对
答案:
4、判断题：
No preheating is recommended during wielding of duplex due to coarse grain.
选项：
A:对
B:错
答案:
5、判断题：
The funciton of Mo is similar to that of Chromium that tends to stabilize alfa-Fe (bcc) and its high-temperature counterpart delta-Fe (bcc).
选项：
A:对
B:错
答案:
第四章 单元测试
1、单选题：
The minimum hardness in the joint of a FSWed precipitation-hardened aluminum alloys lies in the ( ).
选项：
A:thermally affected zone
B:thermomechanically affected zone
C:dynamically recrystallized zone
答案:
2、单选题：
The main alloying element is for 7xxx alloys ( ).
选项：
A:Mn
B:Zn
C:Cu
D:Si
E:Mg
答案:
3、判断题：
Liquation cracking and hydrogen-induced cracking in the PMZ of aluminium alloys are both caused by the combination of a susceptible microstructure and the presence of tensile stresses.
选项：
A:对
B:错
答案:
4、判断题：
Freon has been added to the shielding gas to reduce hydrogen in aluminium welds.
选项：
A:对
B:错
答案:
5、判断题：
Pure aluminum is not susceptible to solidification cracking.
选项：
A:错
B:对
答案:
6、判断题：
Liquation cracking can be reduced by selecting the proper filler metal.
选项：
A:对
B:错
答案:
7、判断题：
The cleaning action of the DCEN cycle helps remove hydrated oxides and hydrides.
选项：
A:对
B:错
答案:
8、判断题：
Adjusting welding sequence is helpful to prevent the formation of weld decay in austenitic stainless steels.
选项：
A:对
B:错
答案:
9、判断题：
A fine equiaxed dendritic structure has a lower susceptibility to cracking than a coarse columnar dendritic structure.
选项：
A:对
B:错
答案:
第五章 单元测试
1、单选题：
Generally, the carbon content of cast irons is generally in the range of ( ).
选项：
A:less than 3 %
B:less than 1.0%
C:larger than 1.0%
D:larger than 2.0%
答案:
2、多选题：
Cast irons can be conveniently grouped according to their structure, mechanical properties and weldability; they are ( ).
选项：
A:C malleable irons
B:D SG graphite cast iron
C:A Grey cast irons
D:B White cast irons
答案:
3、单选题：
( ) is extremely hard and brittle, in which much of the carbon in is retained in the form of iron carbide without graphite flakes.
选项：
A:D SG graphite cast iron
B:A Grey cast irons
C:C malleable irons
D:B White cast irons
答案:
4、判断题：
Casting irons with pearlitic matrix own higher strength than ferritic matrix .
选项：
A:对
B:错
答案:
5、判断题：
Malleable irons are more readily weldable than grey irons.
选项：
A:错
B:对
答案:
6、判断题：
The brazing weld need annealing heat treatment so that it is easily machined.
选项：
A:对
B:错
答案:
7、多选题：
Small welding current is generally recommened for arc cold welding of castings due to ( ).
选项：
A:Small dilution
B:Small heat input
C:Small welding stress
D:Small melting depth
答案:
请先 ！