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This set of Material Science Multiple Choice Questions & Answers (MCQs) focuses on Material Science Set 37
Q1 | which of the following is essential requirement for the galvanic corrosion to occur ?
- an electrolyte in contact with two metals
- electrical contact between two metals
- a difference of potential between two metals
- all of the above
Q2 | which of the following methods are used ot reduce galvanic corrosion ?
- select two metals that are close together in the galvanic corrosion
- avoid relatively small area of less noble metal and large area of more noble metal
- insulate the metal from each other
- all of the above
Q3 | in galvanic corrosion, as the area of anode metal decreases with respect to cathode area of metal, the corrosion rate
- increases
- decreases
- remain constant
- none of the above
Q4 | pitting corrosion is also known as
- low temperature corrosion
- high temperature corrosion
- bimetal corrosion
- none of the above
Q5 | pitting corrosion is also known as
- highly localized corrosion
- low temperature corrosion
- high temperature corrosion
- bimetal corrosion
Q6 | pitting corrosion is a bimetal corrosion, the statement is
- true
- false
- not applicable to it
- none of the above
Q7 | galvanic corrosion is a highly localized corrosion, the statement is
- false
- true
- not applicable to it
- none of the above
Q8 | crevice corrosion is also a localized attack, the statement is
- true
- false
- not applicable to it
- none of the above
Q9 | phenomenon of crevice corrosion is based on
- electrochemi cal corrosion
- electromenta l corrosion
- electromech anical corrosion
- none of the above
Q10 | crevice corrosion rate become faster due to
- gases in the liquid or electrolyte
- high flow of liquid or electrolyte
- trapped stagnant liquids, which is highly concentrated
- none of the above
Q11 | which of the following remedial measure is suitable to prevent crevice corrosion
- avoid joining of metal rivets and bolts. use welding
- avoid solution get into crevice by applying grease
- routine cleaning must be carried out
- all of the above
Q12 | intergranular corrosion take place at which portion of grain
- phases in the grain
- inclusions in the grain
- grain boundary
- twin boundary
Q13 | in case of stainless steels, which type of following effect is seen after welding
- grantization
- sensitization
- graphitizatio n
- none of the above
Q14 | which of the following element precipitate on grain boundary, when stainless steel gets sensitized ?
- vanadium carbide
- molybdenum carbide
- tungsten carbide
- chromium carbide
Q15 | the chemical formula for chromium carbide which precipitate at grain boundary due to sensitization is
- cr23c6
- cr21c5
- cr20c2
- cr0c0
Q16 | in case of intergranular corrosion, when grain boundary become ric in chromium then the % of chromium at the depleted region will become
- lower than 12%
- more than 12%
- equal to 12%
- none of the above
Q17 | when grain voundary becomes sucseptible to corrosion, due to chromium carbide in stainles steel, this stage of metal is known as
- graphitizatio n
- chromitizatio n
- sensitization
- none of the above
Q18 | one of the following is the preventive measure for intergranular corrosion
- use of low carbon grade os stainless steel (304l, 316l grade)
- use of stabilised grade of stainless steel (321 or322 grade)
- use post weld heat treatment
- all of the above
Q19 | one of the following step is used to control intergranular corrosion in stainless steel
- use of metal coatings
- use of cathodic protection
- use of anodic protection
- use of low carbon grade of stainless steel i.e.304l, 316l
Q20 | one of the following step is used to control intergranular corrosion in stainless steel
- use of metal coating, like electroplatin g
- use of stabilized grade of stinless steel i.e. (321, 322grade)
- use of special type of inhibitor
- all of the above
Q21 | what is meant by K.L.A.
- kinetic low alloy
- knife low alloy
- knife line alloy
- knife line attack
Q22 | knife line attack is which type of corrosion ?
- bimetal corrosion
- general corrosion
- intergranular corrosion
- all of the above
Q23 | which of the following ia a velocity related corrosion attack?
- impingement corrosion
- cavitation corrosion
- erosion corrosion
- all of the above
Q24 | one of the following is a velocity related corrosion attack in the pipeline
- general corrosion
- galvanic corrosion
- intergranular corrosion
- none of the above
Q25 | one of the following is a velocity related corrosion attack, due to fluid flow
- impingement corrosion
- crevice corrosion
- bimetal corrosion
- general corrosion