de 300 a 400 Flashcards by TOM GM

Inspection schemes that rely on optical interference patterns include:

(A) holography photography and optical microscopy.
(B) shearography telescopy and image diffraction.
(C) Schlieren photography moire imagery and optical microscopy.
(D) moire imagery holography and interferometry.

(D) moire imagery holography and interferometry.

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Fracture is a type of material failure. Of the following which is another type of material failure?

(A) Fracture mechanics.
(B) Low frequency dynamic loading.
(C) Permanent deformation.
(D) Elongation within the elastic range.
(E) None of the above.

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Which of the following statements best differentiates between a defect and a discontinuity?

(A) Discontinuities can propagate and become defects.
(B) All discontinuities are defects.
(C) All defects will lead to failure if undetected; discontinuities can be harmless.
(D) Discontinuities are external natural boundaries only; defects are internal flaws originating from errors in processing.

(A) Discontinuities can propagate and become defects.

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Nondestructive testing (NDT) is often differentiated from other measurements or inspection techniques in that:

(A) NDT involves indirect tests related to some other quality or characteristic of the material.
(B) NDT is a measurement of dimensions geometry and appearance.
(C) NDT uses electronic instruments to identify evaluate and locate discontinuities.
(D) NDT is an inspection tool used to confirm the findings of the many other quality assurance techniques.

(A) NDT involves indirect tests related to some other quality or characteristic of the material.

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Which of the following describes a function of NDT?

(A) Identification and sorting of material.
(B) Identification of material properties.
(C) Assuring absence of faults or defects that could cause a part to fail.
(D) All of the above.

(D) All of the above.

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An important basis for the success of fracture control design procedures is:

(A) that all flaws are detected by NDT or proof testing before the component enters service.
(B) in the use of large factors of safety.
(C) in the use of a value of strength that the material used in the design is presumed to possess.
(D) the need to assure that unexpected flaws of some critical size are not present when the component enters service.
(E) all of the above.

(D) the need to assure that unexpected flaws of some critical size are not present when the component enters service.

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If properly used NDT can assist in fracture control by:

(A) accurately measuring the tensile strength of design materials.
(B) providing an accurate evaluation of the number and type of discontinuities that exist in a material.
(C) predicting the time it will take a given size discontinuity to grow to a critical size.
(D) all of the above.

(B) providing an accurate evaluation of the number and type of discontinuities that exist in a material.

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A statement that a particular experiment produced a 0.9 probability of detection with a 95% confidence level means that:

(A) there is a 95% probability that the probability of detection is overstated.
(B) there is a 5% probability that the probability of detection is overstated.
(C) on the average 90% of all flaws will be detected.
(D) on the average 95% of all flaws will be detected.
(E) on the average 95 out of 100 flaws will be detected 90% of the time.

(B) there is a 5% probability that the probability of detection is overstated.

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Most solid metals and plastics that have reasonable strength at room temperature are called:

(A) composite materials.
(B) manufacturing materials.
(C) raw materials.
(D) allotropic materials.
(E) engineering materials.

(E) engineering materials.

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Materials properties as used in design are most frequently determined by:

(A) theoretical analysis.
(B) materials testing.
(C) the National Institute of Standards and Technology (NIST).
(D) fracture mechanics testing.

(B) materials testing.

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Even at the early stages of product planning NDT should be considered because:

(A) it may be required by codes and specifications.
(B) the design of the part should permit easy access to critical areas for later inspection.
(C) the materials selected should be compatible with a NDT technique that can accurately evaluate the product.
(D) all of the above.

(D) all of the above.

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Which of the following materials properties are of most concern if corrosion resistance is essential?

(A) Processing properties.
(B) Mechanical properties.
(C) Physical properties.
(D) Chemical properties.

(D) Chemical properties.

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31O. Which of the following is true relative to the comparison of the properties of aluminum-based alloys and iron-based alloys?

(A) Iron has a lower melting point than aluminum.
(B) Iron can exist in several different crystalline structures and its properties can be controlled by heat treatment.
(C) Iron can be alloyed to increase its strength whereas aluminum is strongest in its pure state.
(D) Iron is preferred in load carrying designs but it should not be used for any deformation type of manufacturing process.
(E) All of the above.

(B) Iron can exist in several different crystalline structures and its properties can be controlled by heat treatment.

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Tensile tests are conducted on specimens from a newly developed alloy in order to determine the ultimate tensile strength of the material. Such tests are referred to as:

(A) indirect tests.
(B) physical properties tests.
(C) destructive tests.

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A bar that is 31cm (12 in.) long 51 mm (2 in.) wide and 25 mm (1 in.) thick is subjected to a tensile load acting along the length of the bar of 36 000 lbs. What is the tensile stress within the bar?

(A) 1 500psi.
(B) 3 000 psi.
(C) 12 000 psi.
(D) 18 000 psi.
(E) 36 000 psi.

(D) 18 000 psi.

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In Figure 7.1 point B is called the:

(A) elastic range.
(B) elastic limit.
(C) yield point.
(D) yield strength.
(E) modulus of elasticity.

(B) elastic limit.

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In Figure 7.1 which of the following ranges indicate the effect of work hardening (to its maximum) caused by plastic flow of the material during a tensile load?

(A) A-B
(B) B-C
(C) C-D
(D) D-E
(E) E-F

(D) D-E

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In Figure 7.1 the points represented by E and F would be closer together if the material being tested were:

(A) loaded in tension.
(B) loaded in lap shear.
(C) more ductile.
(D) less ductile.

(D) less ductile.

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The modulus of elasticity or Young’s modulus is a measure of the material’s relative:

(A) tensile strength.
(B) compressive strength.
(C) resistance to stress.
(D) stiffness yield strength.

(D) stiffness yield strength.

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Which of the following materials is typically considered when the application only requires high compressive strength?

(A) Low carbon steel.
(B) High carbon steel.
(C) Cast iron.
(D) magnesium.

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A fatigue failure can often be prevented by using NDT to:

(A) verify the cyclic loading on a component part.
(B) detect surface discontinuities that could be stress risers.
(C) measure the endurance limit of a part undergoing cyclic stresses.
(D) determine percent elongation of a material before it is placed in service.

(B) detect surface discontinuities that could be stress risers.

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Which of the following tests uses a pendulum to break a specimen that is notched and supported on both ends with the result of measuring energy absorption?

(A) Creep test.
(B) Charpy test.
(C) Fatigue test.
(D) Transverse rupture test.

(B) Charpy test.

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Figure 7.2 typifies:

(A) a creep test curve.
(B) an S-N curve.
(C) a stress-strain diagram.
(D) true stress-strain diagram.

(B) an S-N curve.

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Direct hardness tests provide a measure of a material’s ability to resist:

(A) bending.
(B) surface and near-surface penetration.
(C) tensile stresses.
(D) elongation.

(B) surface and near-surface penetration.

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322. A particular type of steel has an ultimate strength of 80 000 pounds per square inch (psi) an elastic limit of 60 000 psi and a yield strength of 62 000 psi. An allowable design stress of 20 000 psi is used. What is the factor of safety based on the ultimate strength? (A) 0.25 (B) 0.33 (C) 3 (D) 3.1 (E) None of the above.

(E) None of the above.

323. Under ordinary usage metals exist as: (A) amorphous solids. (B) mixtures and compounds of iron and carbon. (C) crystalline solids. (D) face-centered cubic lattices.

324. The terms "body-centered cubic " "face-centered cubic " and "hexagonal close-packed" all refer to the: (A) different size grains that can exist at the same time in a metallic structure. (B) sequence of crystalline growth in a typical mild steel. (C) lattice structures that make up unit cells in a solid metallic structure. (D) change in a metallic structure as it undergoes plastic deformation.

325. On Figure 7.3 which intersection describes the "triple point" of the material? (A) (P2 T3) (B) (P2.T2) (C) (Px-Tx) (D) (Pl Tl) (E) None of the above.

326. The process of returning ductility to a cold worked low carbon steel is called: (A) precipitation. (B) recrystallization. (C) allotropic change. (D) austenitization.

(B) recrystallization.

327. Many metals exhibit an increase in strength caused by plastic flow beyond the elastic limit. This effect is called: (A) twinning. (B) plastic deformation. (C) work hardening. (D) recrystallization. (E) age hardening.

328. When used as in-process treatment recrystallization can: (A) improve ductility. (B) refine grains. (C) increase hardness. (D) result in both a and b above. (E) result in a b and c above.

(D) result in both a and b above.

329. Processes called austenitizing annealing normalizing and spheroidizing are: (A) performed only on nonferrous metals. (B) approximate equilibrium heat-treatment processes. (C) cold working processes. (D) age-hardening processes.

(B) approximate equilibrium heat-treatment processes.

330. The terms "precipitation hardening" and "solution heat treatment" are often used interchangeably with the term: (A) age hardening. (B) recrystallization. (C) annealing. (D) work hardening. (E) plasticizing.

(A) age hardening.

331. An NDT method that has the ability to measure changes in electrical conductivity caused by the effects of heat treatment is: (A) magnetic particle testing. (B) acoustic emission testing. (C) eddy current testing. (D) immersion ultrasonic testing. (E) all of the above.

332. Spheroidizing and normalizing have the effect of: (A) increasing ductility. (B) age hardening. (C) reducing the grain size. (D) causing a phase change.

(A) increasing ductility.

333. When a steel has been quench-hardened and then reheated to some point below the lower transformation temperature for the purpose of reducing brittleness this is called: (A) austenitization. (B) thermal slip deformation. (C) allotropic change. (D) tempering.

(D) tempering.

334. Annealing is usually performed to: (A) decrease hardness. (B) increase ductility. (C) relieve stresses. (D) both a and b. (E) all of the above.

(E) all of the above.

335. Attacks on metals by direct chemical action and/or electrolysis are called: (A) rust. (B) corrosión. (C) austenitic transformations. (D) galvanization.

(B) corrosion.

336. Metal corrosion that is accelerated when the metal is under loads is called: (A) pitting corrosion. (B) galvanic corrosion. (C) electrochemical corrosion. (D) stress corrosion.

(D) stress corrosion.

337. Which of the following may be performed to help prevent corrosion? (A) Stress relieving. (B) Anodizing. (C) Dipping in molten metal. (D) Electroplating. (E) All of the above.

(E) All of the above.

338. Factors of safety are often in the range of 2 to 4; they: (A) provide allowances for unexpected loads or conditions. (B) present problems in designing effective aircraft. (C) could be reduced with the assurance of NDT techniques that the material was free of discontinuities. (D) relate to all of the above.

(D) relate to all of the above.

339. The reduction of iron ore by mixing with coke limestone and oxygen for combustion of the coke is accomplished in: (A) a blast furnace. (B) an open-hearth furnace. (C) a Bessemer converter. (D) a basic oxygen furnace.

(A) a blast furnace.

340. In the iron and steel-making process the term "pig iron" refers to: (A) the waste material that contains high concentrations of impurities and slag and is either discarded or used as a by-product. (B) a high carbon low ductility metal that is produced in the blast furnace which can be used to make subsequent types of iron and steel. (C) the molten metal from the blast furnace that is not usable and is poured off into a series of crude castings called "pigs." (D) both a and c. (E) none of the above.

(B) a high carbon low ductility metal that is produced in the blast furnace which can be used to make subsequent types of iron and steel.

341. Which of the following techniques is often used to speed-up the steel-making process? (A) Adding large amounts of carbon to the molten metal. (B) Reducing the amount of scrap steel that is often added to the molten metal. (C) Adding oxygen to the molten metal. (D) Converting the old open-hearth furnaces into electric furnaces.

342. Typically the highest quality of steel is produced in: (A) an electric furnace. (B) an open-hearth furnace. (C) a Bessemer furnace. (D) a basic oxygen furnace.

(A) an electric furnace.

343. What percentage of carbon is found in steel? (A) Between 3% and 4%. (B) Between 2% and 3%. (C) Less than 0.2%. (D) Less than 2%.

(D) Less than 2%.

344. By which of the following processes is most of the world's steel produced? (A) Bessemer converter. (B) Electric furnace. (C) Open-hearth. (D) Crucible. (E) Basic oxygen.

(E) Basic oxygen.

345. An undesirable by-product of steel-making processes is: (A) coke. (B) low carbon steel. (C) low alloy steel. (D) slag.

(D) slag.

346. A steel with 40 points of carbon contains: (A) 40% carbon. (B) 4% carbon. (C) 0.4% carbón. (D) 0.04% carbón.

347. Low carbon steel contains approximately: (A) 0.6% to 2.5% carbón. (B) 0.06% to 0.25% carbón. (C) 0.5% to 1.6% carbón. (D) 5% to 16% carbón.

(B) 0.06% to 0.25% carbon.

348. Corrosion-resistant steels having relatively high percentages of nickel and chromium are called: (A) wrought iron. (B) low alloy steels. (C) stainless steels. (D) nonferrous steels.

349. Austenitic stainless steels are paramagnetic; this means that: (A) alternating current must be used when using the magnetic particle testing method. (B) the steel is very dense and relative to other steels difficult to penetrate with X-rays. (C) ultrasonics is the logical NDT method to choose because of the coarse-grained nature of a paramagnetic material. (D) all of the above are true. (E) none of the above is true.

(E) none of the above is true.

350. Which of the following is an advantage of cast steel over wrought steels? (A) Cast steels usually have higher mechanical properties than wrought steels. (B) Cast steels have more isotropic properties than wrought steels. (C) Cast steels are more corrosion-resistant than wrought steels. (D) Cast steels cannot be heat-treated and are thus less expensive to produce than wrought steels.

(B) Cast steels have more isotropic properties than wrought steels.

351. Which of the following nonferrous metals is the most important structural material? (A) Copper alloys. (B) Nickel alloys. (C) Zinc alloys. (D) Aluminum alloys.

(D) Aluminum alloys.

352. Which oi the following statements is true regarding the electrical conductivity of aluminum alloys? (A) Most aluminum alloys are in the range of 70% to 96% IACS. (B) Clad aluminum takes on the conductivity of the base metal. (C) Each basic wrought aluminum alloy has a conductivity distinct from any other. (D) Both a and b are true. (E) None of the above is true.

(E) None of the above is true.

353. The heat treatment of aluminum for the purpose of hardening and strengthening: (A) is not possible with aluminum alloys because they contain no carbon and cannot undergo allotropic changes. (B) can produce tensile strengths equivalent to some carbon steels. (C) requires the use of special furnaces and is rarely done as a practical application. (D) requires that iron and carbon be alloyed for the best results.

(B) can produce tensile strengths equivalent to some carbon steels.

354. Which of the following metals has low strength high corrosion resistance and is used largely in die casting operations? (A) Aluminum. (B) Magnesium. (C) Zinc. (D) Manganese.

355. Which of the following metal alloys has a density approximately two-thirds that of aluminum ? (A) Magnesium. (B) Beryllium. (C) Copper. (D) Nickel.

(A) Magnesium.

356. Brass and bronze are alloys of zinc tin and a large percentage of: (A) beryllium. (B) copper. (C) lead. (D) nickel.

(B) copper.

357. Monel and Inconel are: (A) nickel alloys. (B) steel alloys. (C) magnesium alloys. (D) aluminum alloys. (E) copper alloys.

(A) nickel alloys.

358. Which of the following metals can typically be used in the as-cast state? (A) Aluminum. (B) Zinc. (C) Steel. (D) Iron. (E) All of the above.

(E) All of the above.

359. A high strength low density corrosion resistant metal alloy of significance in the aircraft marine chemical processing industries is: (A) tungsten. (B) zinc. (C) titanium. (D) Magnesium.

360. Which of the following statements is true concerning plastics following their initial polymerization? (A) Thermoplastics resoften when reheated. (B) Thermosetting plastics do not soften but char and deteriorate when reheated. (C) All plastics are synthetic and contain no natural materials. (D) Both a and b are true. (E) All of the above are true.

(D) Both a and b are true.

361. Based on the strength-to-weight ratio: (A) no plastic materials can compare with metals. (B) some plastics including nylon may have strengths greater than some steels. (C) plastics as a group are superior in strength to most ferrous metals. (D) none of the above are true.

(B) some plastics including nylon may have strengths greater than some steels.

362. Design engineers are responsible for establishing the function appearance quality and cost of a product. Regarding the role of NDT in product design which of the following is true? (A) As a group designers (by their training and education) are adequately informed about NDT to establish NDT procedures and acceptance criteria. (B) When NDT appears necessary in a design the designer should properly select the methods and techniques to be used by reference to NDT handbooks. (C) Designers should depend solely upon NDT personnel to establish acceptance criteria. (D) None of the above is true.

(D) None of the above is true.

363. Manufacturing is a term that refers to processing that starts with raw material in a bulk form and is concerned mainly with processing the raw material in a manner that changes: (A) its shape. (B) its chemical form. (C) its mechanical properties. (D) its physical properties. (E) all of the above.

(A) its shape.

364. Manufacturing processes change raw material by: (A) increasing the material's volume. (B) decreasing the material's volume. (C) solid deformation with no volume change. (D) both a and b. (E) all of the above.

(E) all of the above.

365. Which of the following is true regarding solidification of molten metal in a casting mold? (A) The metal cools at a constant rate thus providing fine equiaxed grains throughout. (B) Cooling takes place in phases having different rates that produce different types of grain structure in different sections of the casting. (C) Solidification occurs at a constant rate beginning at the interior of the casting and progressing outward. (D) Thick sections tend to cool more rapidly than thin sections because thin sections consist mostly of fine equiaxed grains.

(B) Cooling takes place in phases having different rates that produce different types of grain structure in different sections of the casting.

366. In a casting shrinkage occurs: (A) only after the transformation from liquid to solid. (B) only during the transformation from liquid to solid. (C) before during and after the transformation from liquid to solid. (D) only when the metal is in the liquid state.

367. Large voids or porosity in a casting results from: (A) turbulent flow of the molten metal during pouring. (B) alloy element segregation. (C) molten metal boiling because of superheat. (D) gas evolution before and during solidification.

(D) gas evolution before and during solidification.

368. During the solidification of a casting the shrinkage that occurs: (A) may cause porosity and shrinkage cavities primarily in the outer surfaces where the metal cools first. (B) requires that the pattern used be slightly smaller than the desired dimension of the finished casting. (C) may cause cavities that are enlarged by the evolution of gases. (D) may result from all of the above.

(B) requires that the pattern used be slightly smaller than the desired dimension of the finished casting.

369. The design of the casting is important because the quality of the finished product can be adversely affected by the: (A) lack of molten metal to compensate for contraction. (B) location of the gate with reference to either progressive solidification or directional solidification. (C) the location of "hot spots" in areas of the casting that are isolated by thin sections. (D) all of the above. (E) none of the above.

(D) all of the above.

370. The term used to describe a discontinuity in a casting that occurs when molten metal interfaces with already solidified metal with failure to fuse at the interface is: (A) hot tear. (B) cold shut. (C) lack of fusion. (D) segregation.

(B) cold shut.

371. The part of the casting where the gate or riser was attached: (A) should be the area used to establish reference standards for future NDT examinations because this area will contain the best quality cast material. (B) provides the best quality material because of rapid cooling in this area. (C) should be the area that "freezes" first thus preventing excessive shrinkage cavities. (D) may provide a concentration point for discontinuities.

(D) may provide a concentration point for discontinuities.

372. Risers feeders or feed heads in castings serve to provide sources of molten metal to compensate for: (A) misruns. (B) cold shuts. (C) hot tears. (D) dendritic grain growth .(E) shrinkage.

(E) shrinkage.

373. Green sand casting molds include: (A) sand clay and water. (B) sand wax and solvent. (C) sand refractory metals and water. (D) sand carbon and green clay.

(A) sand clay and water.

374. Mold material in the form of inserts that exclude metal flow and thus form internal surfaces or passages in a casting are called: (A) chills. (B) chaplets. (C) cores. (D) Patterns.

375. Small metal supports used to support and position cores become part of a casting by fusing with the molten metal. Such devices are called: (A) core hangers. (B) chills. (C) chaplets. (D) risers. (E) patterns.

376. Which of the following may cause a discontinuity even though its intended purpose is to prevent shrinkage cavities by absorbing heat from the molten metal in the center of the casting? (A) A riser. (B) A core. (C) An internal chill. (D) A chaplet.

377. Which of the following NDT methods can be commonly used to inspect castings for core shift and nonfused chaplets and used to determine that all core materials have been removed? (A) Ultrasonic testing. (B) Magnetic particle testing. (C) Radiographic testing. (D) Eddy current testing. (E) All of the above.

378. Casting molds made by covering a heated metal pattern with sand that is mixed with particles of thermosetting plastic are called: (A) green sand molds. (B) shell molds. (C) plaster molds. (D) die casting molds. (E) permanent molds.

(B) shell molds.

379. Permanent molds are most frequently made of: (A) ceramics. (B) fused sand and plastic. (C) metal. (D) plaster.

380. Another term for precision casting and the lost wax process is: (A) investment casting. (B) die casting. (C) metal mold casting. (D) shell mold casting.

(A) investment casting.

381. A casting process used to produce hollow products like large pipes and hollow shafts is: (A) investment casting. (B) blow casting. (C) core casting. (D) centrifugal casting.

(D) centrifugal casting.

382. A casting process used to produce elongated shapes by drawing solidified metal from a water-cooled mold backed by molten metal is: (A) centrifugal casting. (B) continuous casting. (C) draw casting. (D) extrusion.

(B) continuous casting.

383. An assembly that has been created by joining two or more parts by one or more welds is called a: (A) joint. (B) bonded structure. (C) weld. (D) weldment.

(D) weldment.

384. A general definition of welding describes the joining of two surfaces: (A) with a filler metal that has a higher melting point than the base metal. (B) with a filler material that is different from the base material. (C) in a permanent union established by atom-to-atom bonds. (D) where both heat and pressure are necessary for permanent bonding.

385. Of the following which is not a requirement for fusion bonding? (A) Melting. (B) Atomic closeness. (C) Atomic cleanliness. (D) Pressure. (E) Both b and c.

(D) Pressure.

386. Metallurgical effects in a weld; such as grain size variation and shrinkage are similar to those that occur in: (A) forgings. (B) castings. (C) extrusions. (D) hot-rolled plates.

(B) castings.

387. Pressure welding can be accomplished with pressure alone but what else is usually added? (A) Heat. (B) Filler material. (C) Oxides. (D) Adhesives.

(A) Heat.

388. Proper brazing depends upon numerous factors being controlled. Of the following which is not appropriate? (A) Proper joint fit-up and joint preparation. (B) Adequate heat to melt the braze filler metal. (C) Selection of proper braze filler metal. (D) Complete melting of the step metal and diffusion of the braze filler metal into the base metal. (E) All of the above.

(D) Complete melting of the step metal and diffusion of the braze filler metal into the base metal.

389. Soldering brazing and braze welding all: (A) have the same strength characteristics. (B) use a process where only the filler metal is actually melted. (C) are fusion-type weldments. (D) use liquid penetrant inspection to reveal porosity within the joint.

(B) use a process where only the filler metal is actually melted.

390. Due to high temperatures and rapid rate of cooling the filler material used in fusion welds: (A) is coated with an oxide to help reduce weld defects. (B) contains alloys that will help compensate for properties lost during the welding process. (C) is alloyed with nickel copper and carbon to eliminate cracking. (D) should be as close as possible to the same alloy content as the base material.

(B) contains alloys that will help compensate for properties lost during the welding process.

391. The uneven shrinkage and brittle structures that occur due to the rapid cooling of a weld can often be reduced by: (A) preheating the weldment prior to welding. (B) using a filler metal with a higher carbon content than the base metal. (C) clamping the weldment in a rigid fixture. (D) over designing the size of the weldment to prevent shrinkage.

(A) preheating the weldment prior to welding.

392. After welding many steel weldments are heat treated to obtain more uniform properties between the weld and base metal and to relieve stress. Which heat treatment method is often used following welding? (A) Tempering. (B) Martensitic aging. (C) Normalizing. (D) Spheroidizing.

393. Weldments subject to restraint during welding can develop high residual stresses. Unrestrained weldments can develop: (A) geometric distortion. (B) high residual stresses. (C) cracking after the weld has cooled. (D) all of the above.

(D) all of the above.

394. Welds and weldments have been known to develop cracks long 'after cooling but prior to being used in service. What is the principal cause for such cracks? (A) Accelerated corrosion at high temperature. (B) Scattered porosity in the weld. (C) Improper selection of base material. (D) Excessive residual stresses.

(D) Excessive residual stresses.

395. In arc welding the electric arc is usually sustained between an electrode and the: (A) welding machine. (B) coating on the electrode. (C) work piece. (D) shielding gas.

396. Which of the following gases are most frequently used as shielding to provide an inert atmosphere in the vicinity of the weld? (A) Argon helium and carbon dioxide. (B) Neon tritium and helium. (C) Sulphur dioxide argon and oxygen. (D) Argon nitrogen and hydrogen.

(A) Argon helium and carbon dioxide.

397. When molten metal is transferred from the electrode to the weld zone it can be shielded from the atmosphere by: (A) the burning of coatings on the welding electrode. (B) maintaining the arc beneath flux powders. (C) the flow of a shielding gas around the arc. (D) all of the above.

(D) all of the above.

398. The burn-off rate and amount of spattering during the arc welding process can often be controlled by: (A) proper post-heating of the entire weldment. (B) frequent changing of the tungsten electrode. (C) maintaining the longest arc length possible to reduce the heat in the weld zone. (D) selecting the proper electrode polarity.

(D) selecting the proper electrode polarity.

399. Which of the following welding processes uses a nonconsumable electrode with the arc maintained in an atmosphere of inert gas? (A) Gas Tungsten Arc welding. (B) Submerged Arc welding. (C) Gas Metal Arc welding. (D) Electroslag welding.

(A) Gas Tungsten Arc welding.

400. Shielding in the submerged arc welding process is provided by: (A) gases. (B) granular flux that completely surrounds the arc. (C) a flux-coated welding rod. (D) chopped glass fibers.

(B) granular flux that completely surrounds the arc.