Corrosion Technician Practice Exam

These questions are part of the practice quiz. Start practicing

• Mode of cracking in martensitic stainless steels under hot caustic: which mode?
• Which mechanism primarily affects the activity of cathodic reactions involved in corrosion?
• Which protective measure is commonly effective against stress corrosion cracking?
• Usually with stress corrosion cracking there is a ________ where the crack begins at a microscopic level.
• What term describes brittle failure in an otherwise ductile material due to the combined action of tensile stress and a corrosive environment?
• Protective coatings are particularly effective in controlling uniform corrosion. Is this statement true or false?
• The interior of the pit contains which of the following that are more corrosive than the bulk solution?
• What role does the electrolyte play in galvanic corrosion?
• Ferritic stainless steels tend to be resistant to chlorine stress corrosion cracking, but they may suffer which type of cracking in hot concentrated caustic?
• In general, how does the rate of penetration change as the number of pits increases?
• The galvanic series has been constructed from measurements __________.
• Which of the following is a type of environmental cracking?
• Which type of environmental cracking is hydrogen induced cracking (HIC)?
• Which of the following is a method which interferes with the flow of the current in the electrochemical cell?
• When corrosion rates __________ or __________, long-term projections of corrosion damage are possible.
• Which conducts electrons from the anodic sites to cathodic sites?
• In relation to chlorine stress corrosion cracking, ferritic stainless steels are generally described as
• Which statement best describes galvanic corrosion regarding anodic and cathodic metals?
• Which environment leads to high rates of uniform corrosion in aluminum?
• What is the term for the electrochemical process taking place on the surface of a metal that leads to uniform material loss?
• Crevice corrosion best described as localized attack in restricted environments.
• What is the cathode in an electrochemical cell?
• Which statement describes a lathe-based variation of routing used for the outside of a pipe?
• Crevice corrosion is a form of localized attack in which the size of the attack is an area where free access to the surrounding environment is restricted.
• ________ is attack that proceeds more or less uniformly over the exposed surface with appreciable localization of attack
• Filiform corrosion is a special form of oxygen cell corrosion occurring beneath organic or metallic coating or materials.
• In environmental cracking, corrosion can be found in the cracks, but the metal surface is usually clean with no sign of corrosion. Which two locations are described?
• Weathering steels are low-alloy steels formulated specifically to form tightly adherent, dense corrosion products that inhibit corrosion in some atmospheric environments.
• Which of the following is NOT a factor affecting the extent of accelerated corrosion resulting from galvanic coupling?
• Which corrosive media is listed as promoting stress corrosion cracking?
• Heat treatment causing very high strength leads to susceptibility to chloride SCC in which grade?
• Which statement about initiation and propagation is true?
• Pitting location cannot be predicted. True or false?
• In which environment do the electrolyte resistance limit galvanic effects to the area around the contact?
• Transgranular stress corrosion cracking has been observed in which stainless steel grade under certain conditions?
• Which protection method has been used effectively to control pitting on body exposed surfaces?
• Which term describes stainless steel grades that achieve high strength through precipitation hardening?
• Rates of uniform corrosion of aluminum can be very high in which environments?
• What causes current flow when dissimilar materials are coupled in a suitable electrolyte?
• Pitting occurs at random pits; location cannot be predicted.
• Which statement best describes the drive of pit propagation?
• Transcrystalline stress corrosion cracking is induced in which grades of stainless steel by chlorides especially, and by hot concentrated caustic?
• Environmental cracks are often branched and can propagate along the grain boundaries or across the grains. Which terms fill the blanks?
• In galvanic corrosion, which region is where electrons produced at the anode are consumed?
• Crevices can be either metal-to-metal or metal-to-nonmetal and can be formed under deposits of debris or corrosion products.
• Unlike general corrosion, which occurs at discrete sites on a metal surface?
• Which factor drives corrosion during the propagation step of pitting?
• Depending on the heat treatment, which category of stainless steel may or may not be resistant to chloride stress corrosion cracking; generally the heat treatment that gives alloys a very high strength causes susceptibility.
• Which corrosion mode is deep and narrow and may rapidly penetrate the material?
• Defects that cause pit initiation may be which combination?
• Which form of corrosion occurs at high temperatures forming oxide scales on metals?
• A specialized ammeter used to measure the current flow between the anode and cathode in the external circuit has what type of resistance?
• Another name for crevice corrosion?
• How does increasing pit density affect the overall rate of penetration?
• What happens when a pit fills with corrosion products?
• Which method involves preventing electrical contact between dissimilar metals to control galvanic corrosion?
• Which of the following can be used in underground or immersion situations?
• Crevice corrosion is favored by which condition?
• Which of the following is a flow-assisted corrosion mechanism?
• What are the four stages of pitting?
• In an electrochemical cell, which region is where metal is lost and electrons are produced?
• The four stages of pit development describe which overall process?
• Which grade is described as susceptible to chloride SCC when heat-treated to very high strength?
• The statement 'In structural members where strength is the primary concern, pitting alone may not be as important as in fluid-containing service' is
• Pitting corrosion is characterized by corrosive attack in a localized region surrounded by corrosion-free surfaces, or surfaces that are attacked to a much lesser extent.
• Aluminum and aluminum alloys may be used in applications where localized corrosion does not occur. Is this statement true or false?
• What does PREN stand for?
• Pits are reinitiated when they are ______.
• Which statement best describes galvanic corrosion when two metals are in contact in an electrolyte?
• Which of the following is NOT listed as a factor affecting electrode potentials?
• Propagation along grain boundaries is called what?
• Propagation across the grains is called what?
• Which combination will result in more than one form of corrosion within a system?
• In filiform corrosion the head of the advancing filament becomes ____________ with a low pH and lack of oxygen.
• A pit may terminate due to which of the following?
• Not recommended where pitting may occur?
• Transcrystalline SCC occurs in which stainless steel grade?
• Which of the following is NOT a method to control galvanic corrosion?
• In metal ion concentration cell crevice corrosion the corrosion is usually concentrated at the ______ to the crevice.
• Under which condition do galvanic effects cover essentially the exposed surfaces of both the anode and cathode?
• In a pit-related local electrochemical cell, which electrode is established within the pit and the surrounding surfaces act as cathodes?
• General attack corrosion can be recognized by which surface characteristics?
• Which approach involves changing the environment to reduce galvanic activity?
• Pit initiation occurs at defects or imperfections in what?
• What term describes the brittle failure of an otherwise ductile material resulting from corrosion and tensile stress?
• Which metal ion is listed as contributing to severe corrosion of aluminum equipment when introduced in small amounts?
• In absence of corrosion and tensile stress environmental cracking will not occur.
• A deep, narrow corrosive attack which often cause rapid penetration of the substrate thickness.
• This form of localized attack can occur at crevices where material is meet in such a way that the environment can enter the joint between them but the flow of material into and out of the joint is restricted.
• Pipe and tubing that suffer from general corrosion are
• If there is severe general corrosion, usually SCC will not occur, however when the corrosion products are trapped so as to cause stress in the structure, what will occur?
• Which statement is true about crevice corrosion control?
• Which method is considered the most accurate for measuring pits?
• The more active metal becomes the _____________, while the less active metal becomes the _____________.
• Which statement about pit formation is correct?
• During initiation, pit initiation occurs at which locations?
• What does the direction of current flow depend on?
• General attack corrosion can be recognized by which statement?
• The current flow between the anode and cathode in a galvanic couple is measured using which device?
• Galvanic corrosion can occur between a metal and which type of non-metal?
• Which media cause SCC for commercial titanium alloys?
• What is the purpose of routing in pit assessment?
• Which of the following is NOT a type of localized corrosion?
• Movement of the solution over the metal surface often does what to pitting?
• The cause of filiform corrosion appears to be associated with________.
• Which of the following is NOT one of the nine forms of corrosion?
• Galvanic corrosion can occur under which conditions?
• Cracks in environmental cracking tend to form at right angles to the direction of what property?
• Why is pitting corrosion more difficult to define than general corrosion?
• Which measurement method directly yields the metal thickness loss used to calculate corrosion rate?
• The initiation of filiform corrosion is associated with
• General attack corrosion is best described as which of the following?
• Which of the following is NOT typically a sign of general attack corrosion?
• Amphoteric materials are metals that are chemically vulnerable in both acidic and alkaline environments and can be affected at the cathode in a galvanic corrosion cell.
• Why may corrosion products not always be present with general corrosion?
• Crevices can be formed under deposits of debris or corrosion products.
• Which of the following is NOT a type of environmental cracking?
• Weathering steels are designed to form dense corrosion products that inhibit corrosion in some atmospheric environments. Which material category do they belong to?
• Which type of corrosion occurs on vehicles?
• Electrode potentials are sensitive to factors including electrode composition, electrolyte composition, temperature, degree of agitation, presence of depolarizers or inhibitors, surface conditions of electrodes, and metallurgical conditions of electrodes. Which of the following is NOT a factor?
• In a pit cell, the surrounding surfaces act as which electrode?
• Mode of SCC in austenitic grades due to chlorides especially, and by hot concentrated caustic?
• In oxygen concentration cell corrosion, the area with high cathodic activity will act as the
• To control crevice corrosion, two common approaches are
• A galvanic series is a listing of metals in the order of their potential in a specific electrolyte.
• Which repair can stop the attack before it progresses far enough to cause a significant loss of material?
• Which of the following is NOT a flow-assisted corrosion type?
• General attack corrosion is usually measured in terms of
• Two other names for general corrosion are _______________
• _____________ and __________ are used to control crevice corrosion.
• Which four factors must be present in the electrochemical cell to drive galvanic corrosion?
• Experimental measurement of general attack corrosion is usually made by measuring ________________ and calculating ________________.
• If the cathodic area is much larger than the anodic area, what is the expected effect on the accelerated corrosion rate of the anodic metal?
• Which factor can contribute to reinitiation of pits after rewetting (differential aeration context)?
• Even a single alloy exposed to different environments at different points within a system can undergo _______.
• List three kinds of general corrosion rates.
• When corrosion rates ______________, it is more difficult to predict long-term corrosion.
• Which galvanic corrosion control method uses sacrificial anodes to protect the structure?
• In galvanic corrosion, the cathodic metal's corrosion rate typically does what?
• Filiform corrosion is commonly observed beneath coatings. Which option best describes the area affected?
• Which of the following is a form of corrosion that proceeds uniformly over the surface?
• Which of the following is NOT listed as a factor affecting susceptibility to environmental cracking?
• Stress corrosion cracking is an anodic process, and what protective measure is effective remedial action?
• Crevice corrosion can be driven by differences in which two concentrations?
• Which method removes material from the surface until no further pits are evident?
• The crevice corrosion mechanism driven by a difference in metal ion concentration is known as
• Galvanic corrosion is often pronounced when dissimilar materials are in contact and located where?
• Galvanic effects are usually concentrated where the anode and cathode are:
• Failures resulting from environmental cracking can be unanticipated and catastrophic because they occur in metals selected for their general corrosion resistance (like stainless steels).
• What type of corrosion occurs when metals with different potentials are in electrical contact and exposed to an electrolyte?
• Which type of environmental cracking involves crack growth due to corrosion and cyclic loading?
• With general corrosion, the anodes and cathodes are caused by...
• What term describes environmental cracking that can occur very rapidly and cause failure before inspection can identify damage?
• Which form of corrosion develops on metal surfaces in humid atmospheres?
• The _________ provides reactants for the cathodic reaction and allows the flow of ions.
• Which term describes corrosion caused by contact between dissimilar metals forming galvanic cells?
• Which factor helps explain why galvanic corrosion is often pronounced at sharp edges or corners?
• ________ and _____________ steels perform well in a wide variety of environments, including atmospheric pressure, immersion in natural waters and many chemicals, and underground.
• Pits develop at weak spots in the surface film and at sites where self repair will occur.
• Pitting frequency is defined as?
• In hot concentrated caustic solutions and in some salt atmospheres, stress corrosion cracking of which stainless steel grade has been reported with transgranular cracking?
• For round bars or wires, corrosion proceeds radially inward at essentially a uniform rate around the entire circumference. The result is
• In galvanic corrosion, the anodic metal's corrosion rate typically does what?
• Which pattern of corrosion rate makes long-term projections more difficult?
• Commercial titanium alloys are subject to stress corrosion cracking in which environments?
• Which factor relates to the geometry of the galvanic cell that influences corrosion rate?
• What variation of routing is used to measure the maximum pit depth on the outside of a pipe?
• Which term describes corrosion that occurs at discrete sites on a metal surface?
• What is the anode in an electrochemical cell?
• Which of the following is a form of corrosion that involves selective dissolution of elements in an alloy, leaving a porous structure?
• Ferritic stainless steels are generally resistant to chlorine SCC but may suffer which type of cracking in hot concentrated caustic?
• What is the mechanism of galvanic corrosion described as?
• Which mechanism involves a difference in oxygen concentration between the area inside and outside a crevice, leading to a potential difference?
• What is caused by differences in concentrations of materials?
• The importance of pitting depends on the thickness of the metal; pitting may be serious in which sections and less important in which?
• Which term describes corrosion that occurs at a localized region surrounded by relatively corrosion-free areas?
• Which method uses protective barrier layers to separate metals and slow corrosion interactions?