CHAPTER 23 (Monday) [ REVISION QUESTIO’ CORROSION (Answer of question from course notes) Qo. Ans- Q02- Ans- Q03- Ans- Q04 Is the electrical circuit in a corrosion reaction AC or DC? ‘Does cormsion occur at the cathode or anode? Name the three factors needed for corrosion to occur. ‘What is meant by the term electrolyte? What is corrosion? In the corrosion circuit do electrons flow from anode to cathode? Which gas is released af the cathode when the electrolyte is water? which is more noble metal, steel or aluminium? Steel or aluminium? Which is more clectronegati If steel and copper were in contact in electrolyte which would corrode? a ff z g 5 & =z 3 é 3 : e Name three metals used as sacrificial anode on a steel pipeline. ‘What is the approximate thickness of millscale? Which of the two metals would corrode if steel and zine were coupled? Which other names relate to the Galvanic list?Q16 Ans- Quy Ans ais Ans- Qi. Qu Ans- Q25- Ans Q26 Ans Q27- Ans Q2s- Ans- Q2 Ans: Q30- Ans- In which environment are you likely to encounter chloride salt? Marine's environment. Which three compounds together form millscale’? ‘Wustite, Magnetite and Hematite. If magnesium was coupled with zine, which would corrode? Magnesium, Jn which environment would sulphate salt be found’? Industrial and agriculture. What is an osmotic blister? ‘Dome shape projection causes by Hygroscopic Salts What is an ion”? What is meant by polarization? Is an anode positive oF negative? Can comosion oceur without an electrolyte? Name a subatomic panicles. What is millscale and when and where does it occur’? Name three factors, which can accelenite corrosion reactions, z =z 2 & z g é zg EB & 2 2 8 = z E E E = 2 g 2 z g & = 2 = g & & 8 2 EB E & e 8 3 = Ie corrosion accurs at anodic areas, why does steel corrode evenly all overthe surface?CHAPTER 25 (Monday) Sht 2 [ REVISION QUESTIONS SURFACE PREPARATION (Answer of question from course note) Qol- Ans- Q02- Ans- Q03- Ans. Q04- Ans- Q0s- Ans- Q06- Ans- 8 S = : = 5 z & Ans- 8 Zz : Z g R z z E = g a z Ans- Qn. Qu Ans- Que Qs Ans. ‘Which British standard would be used in determining the size of copper slag abrasive? Which British standard would be used in determining the size of metallic abrasives? Which regulations probibit the use of sand for blasting stee!? What is meant by the term *key"? Why is it important to have good surface preparation? What is meant by the term ‘silver"? A 9 z z e 3. What are the main advantages of using *Testex papers” for measuring profiles? ‘What is meant by the grade, relating to a blast finish’? ‘What are the main factors governing the grade of a blast finish? Can the grade of a blast finish be determined by using the surface comparators to BS7079 Pt C3? ‘Whit profile range can be measured using X course Testex? ‘What profile range can be measured using course grade Testex? = E & g i 2 e 5> | ze Qis- Ans: Qi9- Q20- Q25- Ans Q26- Ans Qu7- Ans: Q28- Ans: r ow many microns are in | thou? Give three different names for the cross section of a blast, What is the approximate speed of abmsives leaving a venturi nozzle? What is the most common cause of flash rusting on a blasted substrate? What would be considered to be an ideal shot grit mix? z = a F 2 a 2 & sg Z a z e S z i 5 2 § 2 Which abrasive would have the effect of work hardening? Name three methods of measuring or assessing a profile, What is the most common cause of rough peak on substrate”? In what situation would it better to use steel grit in preference to copper slag abrasives? ck or l strate after blasting what step should be taken? = 5 E z z a z z z 8 g 5 E Using comparators to [SO 8503, what are the thee main profile assessments?Q29- Ans- Q30- Ans- what are the other two assessments when the above three are not appropriate? What would be size of copper slag needed to give a profile of 50 to 75ym Carne. (G16) Be & Soup CONVERTER PDF) Samra SURFACE PREPARATI (Answer of question from course note) ‘Whiat is the title of the BS 70797 What are the four characteristics of an abrasive? Why are blast hoses carbon impregnated? Name the gauge used for measuring pressure at the blast nozzle? ‘Name fouradvantages of centrifugal blasting over open blasting. According to BS 7079 it is possible to blast clean to an A Sal? Is there any difference between an A Sal and B Sal? ‘Could you tell the difference between rust grades A and B blasted to Sa3? ‘Could you tell the difference between rust grades C and D blasted to Sa3? ‘What would be a typical speed of abrasives leaving a wheel abrator?QI2- What is meant by the term “burnishing”? Any Bumishing is a result of over brushing, smooth and shiny areas which does not provide good QU What would be the equivalent to $2 in the Sa grade? Ans- SAU QI4- What is the neutral figure on the pH scale? Ans- §pfl QIS- How is pH measured? Ao TE Ge & SOLID CONVERTER PDF» Sacnmenes QI6- Why are inhibitor sometimes added tw water in wet blasting? > 5 & QI7- Name two typical areas where needle guns might be used? > 5 ¢ QI8- What is the Duplex process of surface preparation? Any Pickling process followed by passivation proces. QI9- Which pH range covers acids? Ans- OG PRNAG Q20- Which pH ninge covers alkalies? Ans- (GSA REAURSIES Q21- What is the meaning of pH? 22- Name three disadvantages of wet blasting’? > z 1¢ two areas on «structure where flam cleaning cannot be done? A Daten ee Ra deQa Ans- EL 3) SOLID CONVERTER PDF Q32- Q33- Q35- Q36- Which three basic operations are performed during flame cleaning? How does BS 7079 define flam cleaning standanls? What is “Jason Hammer? What is meant by St? and S13? Two alloy are use to render wire brushes spark free, what are they? Why “Burnishing” be avoided? Name two disadvantages of using needle gun. After phosphating, what would be a typical pH requirement prior to coating? What is under stood by the term “Knock out pot? If an operator was blasting with a nozzle pressure of 80 psi. What would be his approximate efficiency? Which solvents are commonly used for degreasing? What is the dead mans handle? Why is carbon impregnated in to blast hose?Ans- Q42- Qu. Ans- Qu. Ans. z | ! i What is the main disadvantage of high pressure jetting compared to other systems? Name five method of wet blasting. What would be typical temperature and concentration of sulfuric Acid in the pickling process’? Describe the ‘Duplex processes’. What would be maximum pressure for high pressure water jetting? What are the disadvantages of wet blasting over dry blasting? Describe the phosphating process?