20 interview questions for welding operators

20 interview questions for welding operators  Interview questions for welders

A collection of questions related to welding and their answers which can be important for interviewing a welder.

Question-1 What do you mean by welding?

Answer- Welding is a process of joining two or more metals together by heating and/or pressure.

Question-2 What do you know about GTAW?

Answer- GTAW "Gas Tungsten Arc Welding" It is an Arc welding process wherein fusion is done by heating the job with an electric arc struck between a tungsten electrode and the workpiece where shielding gas is used to avoid atmospheric contamination of the molten weld pool.

Question3- What is the content of tig welding?

Answer- A torch with its accessories like a hose for argon gas, welding leadceramic nozzle, collet body and collet, high-frequency switch, tungsten electrode.

             A Gas cylinder with its accessories like Regulator with Pressure Gauge, hose pipe.Regulator with Pressure Gauge (HP & LP) and flow meter.
             A Transformer / Rectifier. with power cable, Filler wire, grinder machine.

Question 4- What is SMAW?

Answer- SMAW "Shielded Metal Arc Welding" It is an Arc welding process wherein fusion is done by an electric arc between a flux covered electrode and the job. in this process, the electrode melts itself and fills the joint, flux covers the weld pool in the form of a  slag that prevents atmospheric contamination.

Question 5- How will you calculate current for SMAW  Process?

Answer-The thumb rule for calculating welding current is
 "welding current=40* Dia of  electrode ± 20"

Question 6- What is the full form of IBR?

Answer-  IBR: Indian Boiler Regulation Act.

Question 7- Why do you leave a hole or some part of welding during the welding of a re-inforcement pad?

Answer- To exclude hot gas which may be generated due to welding.

Question 8- What is WPS?

Answer- WPS "Welding Procedure Specification" It is a written document that provides direction to the welder or welding operator to get sound weld repeatedly.

Question 9 What are the different ASME code sections?


SECTION I- Rules for Construction of Power Boilers
SECTION 3- Subsection NCA General Requirements for Division 1 and Division
Division 1
Subsection NB-Class 1 Components
Subsection NC-Class 2 Components
Subsection ND - Class 3 Components
Subsection NE - Class MC Components
Subsection NF – Supports
Subsection NG - Core Support Structures
Subsection NH - Class 1 Component in Elevated Temperature Service-
Division 2 - Code for Concrete Containments
Division 3 - Containments for Transport and Storage of Spent Nuclear Fuel And High-Level Radioactive Material and Waste
SECTION IV- Rules for Construction of Heating Boilers
SECTION V- Non-Destructive Examination
SECTION VI- Recommended Rules for the Care and Operation of Heating Boilers
SECTION VII- Recommended Guidelines for the Care of Power Boilers
SECTION VIII- Rules for Construction of Pressure Vessels
SECTION IX- Welding and Brazing Qualifications
SECTION X- Fiber – Reinforced Plastic Pressure Vessels
SECTION XI- Rules for In-Service Inspection of Nuclear Power Plant Components. SECTION XII- Rules for Construction and Continued Service of Transport Tanks.

Question 10-How many types of welding defects occur in welding operation?Answer- Common Welding Defects can be classified as follows:

  • Lack of penetration
  • Lack of fusion
  • Crack
  • Inclusion
  • Distortion
  • Reinforcement 
  • Undercut
  • Porosity
  • Blowhole
  • Arc blow
  • Burn through
  • Faulty welding profile

Question 11-How many common things are included in the welding procedure specifications?

Answer-        Pipe Dia & Thickness, Pre Heat, PWHT, Welding PositionHeat Input, Consumable, Material Group Process.

Question 12-What is the test position?

Answer- Test Position for plates:-

Flat Position 1F
Horizontal Position 2F
Vertical Position 3F
 Overhead Position 4F

Test Position for Pipes:-

A. Flat Position 1F

B. Horizontal Position 2F
C. Horizontal Position 2FR
D. Overhead Position 4F
E. Multiple Position 5F

Pipe Positions: -

A. Flat Position 1GB. Horizontal Position 2GC. Multiple Position 5G
D. Multiple Position 6G

Question 13-What is the meaning of E7018?

E= Electrode ,70=Tensile Strength,1 =for all Position,8 = Coating

Question14- Why the electrode E7018 is called low hydrogen electrode? 

Answer:-E7018 is a low hydrogen electrode  
 because it has an ingredient in their coating, which produces carbon-di-oxide during melting. This CO2 gives a gaseous shielding for the metal and prevents atmospheric hydrogen from entering an arc atmosphere. In this way, the weld metal has a low level of hydrogen.

Question 15- What will happen if more quantity of hydrogen absorbed in weld metal?

 When hydrogen is included more in weld metal it can make the material brittle and subsequently leads to cracks, which is called hydrogen-induced cracks or delayed cracks.

Question 16-How to avoid hydrogen-induced cracks or delayed cracks?

Answer:- By using backed electrodes we can eliminate these types of cracks.

Question 17-What is the backing process for welding electrodes?

Answer:- Basically the electrodes should be backed at 250૦ to 300 ० in mother oven for one hour after that it should be cooled down at 100० in the same oven and than transfor to the portable oven where the temperature should be maintained at 60 ० to 70० during the welding operation.

Question 18-What is PWHT?

Answer:- Post weld heat treatment , this is done to remove residual stress left in the joint due to the welding operation.

Question 19- What is Steel?

Answer:- A mixture of carbon and iron called steel.

Question 20- What are the Type of Common Welds?

Answer:-        Groove Welds
                       Fillet Welds
                       Spot / Seam Welds
                       Plug / Slot Welds
                       Edge Welds


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