124 EXAMINATION QUESTIONS

A COURSE IN WELDING SUPERVISION AND INSPECTION

provided by

Technolkonstrzębski Co Sp. z o.o. in Krakow

 

Sample answers:

In what cases is the dehumidifying preheating of the root of a joint applied? In the case of high humidity, dew, and welding of fine-grained steel.

In what way are the welding parameters of traditional welding equipment set and corrected after the  sheet metal becomes heated?  For a preset voltage (bead width), the wire feed speed is regulated in such a way as to ensure that the drops become detached at regular intervals and their splash while passing through the weld pool is heard as a continuous humming noise. After the sheet is heated, the electric arc extends and the bead widens. The arc voltage has to be then reduced.

How can the lack of joint penetration be detected while watching the welding process from the side of the root from the distance of 20m? When no crossing of the arc to the other side is detected and no characteristic after-sound in the pipe is heard, then there is no penetration.

 

Theoretical questions

^{1. Which parameters of MAG welding (current, voltage) are set on the welding machine and which are set on the feeder?}

^{2. What happens to the arc length when the voltage on the MAG welding machine is increased?}

^{3. What happens to the fusion, bead width and the thickness of weld reinforcement when the voltage is increased?}

^{4. What are the advantages of a four-roll system of wire feeding?}

^{5. Name the wires for MAG welding of  St3S and 18G2 steels.}

^{6, What is the impulse-synergic welding machine?}

^{7. What are the advantages of the impulse sources of MAG?}

^{8. What is St3S steel?}

^{9. What are the effects of the increase in the wire feed speed?}

^{10.  Decipher the following symbols:}

     ^{B2, 1C    and        EN 287 – 1 135 P BW W03 wm t10 PF PA ss nb}

      ^{P1E          and        EN 287 – 1 111 P FW W01 RR a5  PB}

     ^{R3, 2T       and       EN 287 – 1 141 T BW W11 wm t6 D60 PF PC ss nb}

^{11.   What the voltage  and drooping characteristic of a welding machine?}

^{12.   What is  the short-circuit and spray metal transfer?}

^{13.      What are the tasks of welding supervisors?}

^{14.     How is the face of a weld marked on drawings?}

^{15.    How is the transcrystalline structure of a weld dealt with?}

^{16.    What do the welding stresses depend on?}

^{17.    What current is used in TIG welding of aluminium?}

^{18.    How many welds are tested by means of visual inspection (W)?}

^{19. Principles of classification of parent metals and consumables, used by PRS and other classification societies}

^{20.     Principles of issuing qualification certificates (UDT, PRS, IS, SLV) to companies.}

^{21. How do the Polish Standards concerning welder training differ from the European Standards?}

^{22.      What requirements must a welder meet in order to weld mechanical building structures of class 2 and 3?}

^{23.     What are the classes of building structures in accordance with PN-97/B-06200?}

^{24.    Requirements concerning the qualification certificates and the system of quality assurance of companies manufacturing constructions of class 3 in compliance with PN-97/B-06200:}

^{25.     Requirements concerning the qualification certificates and the system of quality assurance of companies manufacturing constructions of class 2 in compliance with PN-97/B-06200}

^{26.     Requirements concerning the qualification certificates and the system of quality assurance of companies manufacturing constructions of class 1 in compliance with PN-97/B-06200}

^{27.    What is the differnece between pWPS, WPAR ( PQR in the USA)  and WPS?}

^{28.    What is the scope of approval for European Welders concerning the thickness, diameter and the position of welding?}

^{29  What do the abbreviations AWS i ASTM stand for in the catalogue of materials?}

^{30.  What are indicators?}

^{31.  Name the classes of  welded industrial constructions in accordance with PN-87/M-69008.}

^{32.   What is the weldability of  18G2 , 15HM, 10H2M and 65G steels?}

^{33.    What do the symbols R2 and U3 stand for?}

^{34.   How can a high strength of constructional steels be ensured?}

^{35.   What do the symbols B, C, D denote?}

^{36. What causes the cold and hot weld cracks: stress or shrinkage? Are they characteristic of stainless or carbon steels?}

^{37. What is the application of the mechanics of cracks?     What is responsible for the heat transfer from the arc to the welded material: thermal conductivity or radiation?}

Practical questions

^{1.       What  are the consequences of the wear of the hole of the electric tip in MAG welding?}

^{2.      When does the mixture suck in the air between the wire and the wire guide in MAG welding?}

^{3.     To what end and in which place on the MAG welding machine is inductance set?}

^{4.       Where is a higher voltage required in MAG welding: in CO2 or in the mixture?}

^{5.       What causes incomplete fusions?}

^{6.       What does the amount of the feed gas depend on?}

^{7.       What are the defects characteristic of MAG welding in CO2?}

^{8.       Into what categories can companies be divided in accordance with PN-87/M-69009 as far as the welding procedure is concerned?}

^{9.       How does the beading by means of setting the voltage differ from the beading by means of wire feeding (in MAG welding)?}

^{10.    What types of beads in the PF position are not acceptable during the examination test for a welder in the material group W03?}

^{11.    What method of welding (111 or 135 ) should be applied  when welding a converter with the thickness of the walls}

 ^{of 120mm.}

^{12.    What are the characteristics of MAG welding with a cored wire?}

^{13.     How does the backing for  welding of steel differ from the backing for welding of  aluminium?}

^{14.  What type of groove (V groove or Y groove) should be prepared for welding with a backing?}

^{15.   What is the shrinkage of a 10 running metre weld with a thickness of 10mm:?}

^{16.    Which defects are more dangerous  in the case of a dynamic load: external or internal ones?}

^{17.     What are the advantages of fine-grained steels produced in the process of thermoplastic treatment?}

^{18.    In what way are fine-grained steels welded?}

^{19.    What is the method of performing the penetration in pipes with the changing load of pressure above 200 atmospheres?}

^{20.    What is the transcrystalline structure of a weld and how does it differ in  stainless and carbon steels?}

^{21.     In what way are carbon steels welded with acid resistant steels?}

^{22.     How can  stratification be avoided while welding metal plates?}

^{23.    How can welding deformations be avoided?}

^{24.    What method should be used when welding sheet metal (0,8mm)?}

^{25.   To what end and in what way is the suction  of a welding torch verified?}

^{26.     How is welding in fuel tanks performed?}    

^{27.    How are the consumables for the welding of stainless and carbon steels and aluminium selected?}

^{28.   In what way are aluminium pipes bevelled and tack-welded?}

^{29.    What type of electrode is used when welding 10H2M, 18G2A steels and 14HMBCu fine-grained micro-alloyed steel?}

^{30.   In what way is  penetration performed in sheet aluminium with a dynamic load?}

^{31.     What is the maximum unevenness of the filling layers acceptable for the laying of the next bead?}       

^{32.    What should be the arc length in the case of performing the penetration and forming  the face of a weld in TIG welding?}

^{33. In which place is weld metal added while forming the face of a weld in TIG welding?}

^{34.   How can the welded metal be protected against delayed cracking when the hydrogenation was found to be too high?}

^{35.    In what way is the bottom of a tank welded?}

^{36.     The principles of welding of a fuel  tank shell.}

^{37. The principles of welding bridge girders.}

^{38.    The principles of using the automatic welding machines in an assembly process.}

^{39.    How can the angular deformation of a weld be reduced?}

^{40.    The principles of assembly and welding of spherical tanks.}

^{41.    In which cases is the dehumidifying preheating of the root of a joint applied?}

^{42.    Which defects are more dangerous  in the case of a dynamic load: external or internal ones?}

^{43.     What are the advantages of fine-grained steels produced in the process of thermoplastic treatment?}

^{44.    In what way are fine-grained steels welded?}

^{45.    What is the method of performing the penetration in pipes with the changing load of pressure above 200 atmospheres?}

^{46.    What is the transcrystalline structure of a weld and how does it differ in  stainless and carbon steels?}

^{47.     In what way are carbon steels welded with acid resistant steels?}

^{48.     How can  stratification be avoided while welding metal plates?}

^{49.    How can welding deformations be avoided?}

^{50.    What method should be used when welding sheet metal (0,8mm)?}

^{51.   To what end and in what way is the suction  of a welding torch verified?}

^{52.     How is welding in fuel tanks performed?}    

^{53.    How are the consumables for the welding of stainless and carbon steels and aluminium selected?}

^{54.   In what way are aluminium pipes bevelled and tack-welded?}

^{55.    What type of electrode is used when welding 10H2M, 18G2A steels and 14HMBCu fine-grained micro-alloyed steel?}

^{56.   In what way is  penetration performed in sheet aluminium with a dynamic load?}

^{57.     What is the maximum unevenness of the filling layers acceptable for the laying of the next bead?} 

^{58.What should be the arc length in the case of performing the penetration and forming  the face of a weld in TIG welding?}

^{59. In which place is weld metal added while forming the face of a weld in TIG welding?}

^{60.   How can the welded metal be protected against delayed cracking when the hydrogenation was found to be too high?}

^{61.    In what way is the bottom of a tank welded?}

^{62.     The principles of welding of a fuel  tank shell.}

^{63. The principles of welding bridge girders.}

^{64.    The principles of using the automatic welding machines in an assembly process.}

^{65.    How can the angular deformation of a weld be reduced?}

^{66.    The principles of assembly and welding of spherical tanks.}

^{67.    In which cases is the dehumidifying preheating of the root of a joint applied?}

^{68.   What requirements have to be met in order to eliminate blowholes in TIG welding during an assembly process?}

^{69.    What is the difference between leading the torch in MAG welding in CO2 and in the mixture?}

^{70.    How can incomplete fusions be predicted?}

^{71.    What equipment is needed for the welding of  creep-resisting steels in power stations?}

^{72.    What are the principles of tack welding?}

^{73.    What method is used for welding the leakproof waterwalls of steam boilers?}

^{74.    In what way should the face of a weld be laid in order to avoid undercuts?}

^{75.    How can a blowpipe in a weld performed by means of the methods 311 and 141 be removed?}

^{76.    What parameters of MAG impulse welding should be corrected after the welded metal becomes heated: the impulse parameters or the current of the base of the impulse.}

^{77.   What is the transverse shrinkage of the vertical weld of a tank with a  plate thickness of 10mm and 40mm respectively?}

^{78.    What is the sequence of operations for the welding and tack welding of tank plates with a thickness of 12 mm?}

^{79.    How can the lack of undercuts of the face and the root of a weld be checked?}

^{80.    What causes the undercuts of the root of a weld?}

^{81.    At what  distance from the joint do the temperature of  the plate surface and the condition of the surface (heat insulation of the old plate, hoarfrost covering, marring )  influence the intensity of base metal melting, and what distance influences the quenching of the joint?}

^{82.    What is the difference in the method of preparing patches, the method of bevelling, the welding sequence  and the tack welding sequence for a layer of plates with a thickness of 10mm and 40 mm respectively?}

^{83.   Which parameters (the current of the base or the impulse parameters) should be set  after the plate becomes heated?}

^{84.    What tools are used when preparing aluminium constructions for welding?}

^{85.   What arc length and what angle of view should be maintained while welding with a coated electrode?}

^{86.   At what distance from the preceding bead should the weld pool be run in order to obtain a smooth face of the weld?}

^{87.    With what speed should the welding arc in MAG welding be led so as to avoid  metal spattering?}

^{88.    What should be the minimum speed with which the  torch in MAG welding should be led so as to avoid incomplete fusions between the beads?}

^{89.    How to distinguish the dangerous active cracks from the cracks which are safe after the stress relaxation takes place?}

^{90.    Which technique of  MAG welding: pulling the arc or pushing the arc is more effective in eliminating incomplete fusions?}

^{91.     What causes the stress cracking of the surface of an acid-resistant tank to the depth of 2mm?}

^{92.    What problems can be expected following the welding of  high-strength steels produced in the process of thermoplastic treatment?}

^{93. What determines the crack sensitivity of micro-alloyed steels?What advise can be given to a welder in the case of the lack of  penetration in MAG welding: to lead the torch faster or more slowly?}

94. How can the lack of the joint penetration be detected while watching the welding process from the side of the root from the distance of 20m?^?

^{95. What determines the intensity of base metal melting and what influences the heating of the base metal to the temperature of wettability (the lack of undercuts)?}

^{96. In what way are the welding parameters on the traditional MAG welding equipment set and how are they corrected after the plate becomes heated?}

^{97. What methods can be used in vertical down welding so as to avoid the incomplete fusions caused by the liquid metal coming up to the front of the welding arc?}

^{98. What defects are admissible while welding constructions with a static load and inadmissible while welding cranes with a dynamic load and steam collectors?}

^{99.What are the differences between the requirements concerning the leak tightness of gas and steam pipelines?}

^{100. Why do the welds of bridge spans crack on the side subject to tensile stress, and the welds of crane girders on the side subject to compressive stress?}

^{101. Why do welding deformations differ depending on the company in spite of using the same welding procedure and employing the same specialists ?}

^{102 How can deformations be avoided while welding the thin-walled box beams?}

^{103. What causes the buckling of the thin-walled constructions during welding?}

^{104. What is more important in welder training: to learn how to maintain the specified length of the welding arc or how to maintain the size and shape of the weld pool?}

^{105. How do the cracks, the thickness of the root face and the travel of the toe in relation to the diameter of the weld metal influence penetration?}

^{106. What is the difference between the method of performing penetration by means of a coated electrode and in MAG welding?}

^{107. What is the difference between  the way weld metal is added in PC position in TIG welding and in gas welding?}

^{108.Why do gas welders have problems with performing a high-quality penetration of stainless pipes in TIG welding?}