Quality Control Mechanical Interview Questions

This article is about Quality Control Mechanical Interview Questions related to topic of Mechanical Inspection as per Saudi Aramco or International Standards. This questions can be useful for who are attending CBT Aramco Test or other international test for Mechanical QC Inspector or Engineer.

Quality Control Mechanical Interview Questions | CBT Aramco

What is MILS?
Ans. Thousand of an inch
Give at least 3 essential variables of WPS?
Ans. Electrode, preheat, volt/amp, position, base metal
What is WPS?
Ans. Welding Procedure Specification- a prepared welding procedure which serve as guidance of the welders
What is WPQ?
Ans. Welders Performance Qualification- is the performance testing of the welder capability to do the weld in accordance with approved WPS
What is PQR?
Ans. Procedure Qualification Record- a record of welding data used to weld a test coupon
What is PMI?
Ans. Positive Material Identification- a process use to determine the constituents of a materials
What is HAZ?
Ans. Heat affected zone- a portion of base metal that was not melted during welding process but whose microstructure & properties were altered by heat
What is PWHT, its purpose?
Ans. Post weld heat treatment- to relieve internal stress that has trapped inside the weld during welding process
What is purpose of preheat?
Ans. To slow down the cooling rate, to reduce hardness of the weld to avoid cracking & brittleness
What is interpass temperature?
Ans. The highest temperature in the weld allowed prior to interpass weld in the case of multiple pass weld
What essential variables in WPS?
Ans. A change in welding condition which will affect the mechanical properties of the weldment.
Why maintenance temperature is very important for austhenetic materials?
Ans. To reduce intergranuallar corrosion near the weld
What is hardness in accordance with NACE MR0175?
Ans. 22 HRC maximum @ 620 degree (Rockwell C hardness)
Type of toughness test?
Ans. Charpy V-notch, IZOD, CTOD (Crack Tip Opening Displacement)
Type of hardness test?
Ans. Rockwell, Vickers, Brinell
What mechanical test is an additional requirement for materials in low service temperature?
Ans. Impact test
What toe cracks is?
Ans. Generally cold cracks a results of thermal shrinkage stress acting on the weld HAZ
Differentiate between discontinuity & defects?
Ans. Defects- a discontinuity which exceed the permissible limit in relevant code Discontinuity- irregularity in the normal pattern of the weld metal not necessary a defects
Prevention before using low hydrogen electrode?
Ans. Electrode shall be dried at 260 degree ~ 430 degree for 2 hrs. and shall stored continuously in the oven at 120 degree
What is GMAW?
Ans. Gas Metal Arc Welding- often called MIG (Metal Inert Gas) welding. Widely use as semi- automatic joining process w/c coalescence of metal is produce by heat from an electric arc that is maintained between the tip of a consumable bare wire electrode and surface of the base metal in the weld joint.
What is FCAW?
Ans. Flux Cored Arc Welding- its similar to GMAW, FCAW have the highest deposition rate & semi-automatic welding process w/c coalescence of metal is produced by heat from an electric arc & maintain between the tip of consumable flux filled wire electrode & surface of the base metal in the weld joint
What is SAW? Ans. Submerged Arc Welding- Referred to as (Submerged) because electric arc is actually submerged under the granular flux, currently use for thick metals & heavy steel fabrication
What is the acronym GTAW, describe the process? Ans. Gas Tungsten Arc Welding- which often called TIG (Tungsten Inert Gas) welding, can be manual joining process in w/c coalescence of metal is produced by heat from an electric arc that is maintain between the tip of a tungsten electrode (non consumable) & the surface of base metal in the weld joint.
What is SMAW? Ans. Shielded Metal Arc Welding- its commonly called stick welding, widely use arc welding process w/c coalescence of metal is produced by heat from an electric arc that is maintain between the tip of a covered electrode & surface of base metal in the weld joint
What is a straight face in a size of 3mm in Bevel?
Ans. Root Face
It is need to qualify the welder, if the WPS is pre-qualified in the same project?
Ans. No
What NDT which use illumination for testing? (RT not included in the choices)
Ans. Magnetic Particle Test (MT)
Give at least 3 “attributes” that could result form tension test.
Ans. Ultimate tensile strength, yield strength, and percent elongation
Enumerate at least 5 essential attributes in material test report (MTR).
Ans. Material specification/grade, mechanical properties, chemical properties, heat number, name of manufacturers
Why there is a need to specify maximum interpass temperature for austenitic stainless steel?
Ans. To avoid excessive heat input
Why is it 3mm root face (in groove preparation) is important in most weld joint?
Ans. To avoid melt through weld, burn through, root concavity.
What is the minimum mechanical test required to qualify a welder?
Ans. Bend Test
What is the effect of Hydrogen on the weld metal?
Ans. Cracking/Brittleness
Define the meaning of Overlap?
Ans. A form of lack of fusion that occurs in the weld face area during the positional welding caused by action of gravity.
What is Acid Test?
Ans. It is a Non-Destructive Test applied in cladded plate after removing of stainless to carbon steel.
What are the 4 grooves joint and each positions?
Ans. 1G – Flat; 2G – Horizontal; 3G – Vertical; 4G – Overhead
How do you preserve electrodes after it has been removed from its container before using?
Ans. Holding oven
What is Autogenous Weld?
Ans. A type of welding process that do not use filler metal.
Where does porosities be obtained?
Ans. Atmospheric contamination; chemical contamination
When welding of high nickel content material, the electrode to be used always lower in nickel content than the base metal.
Ans. False
What is the most automated NDE process?
Ans. Eddy Current
If there is no accessability to do the weld at the back side of the joint. What welding process can be used?
Ans. GTAW
If there is no accessability to do the weld at the back side of the joint. What discontinuities mostly can be found?
Ans. Lack of fusion; Burn through; Root concavity
What is the necessary requirements for the inspection of instruments?
Ans. Calibration Certificates, Check the calibration date.
Is it required to Qualify Procedure Specification if there is a chance in the Essential Variable?
Ans. Yes
Where does hydrogen can be obtained?
Ans.Rust, moisture, oil/grease
When you found a weld repair and make a weld report, to whom will you address the report?
Ans. Welding Foreman
For non magnetic materials, What NDT method can detect surface cracks?
Ans. PT
Where can you find Toe of the weld?
Ans. Junction between face and weld metal.
When a vendor received a P.O. from a client which have conflicts from a code and standard requirements. Does the vendor require to accept?
Ans. False
What NDT method used to detect Lamination?
Ans. UT
What are the important traits of an inspector?
Ans. Informed, impartial,….
In AWS D1.1, Pre-qualified Welding Procedure does not need to qualify a welder (true or false)?
Ans. False
In AWS D1.1, Pre-qualified Welding Procedure does not need to qualify a welder (true or false)?
Ans. False
According to AWS D1.1, all welding procedure needs to be qualified? (True or False)
Ans. False
In doing the inspection for size of the fillet weld, what is the reference that you will use to make sure that the you are checking the right size of the fillet weld?
Ans. Fabrication drawing
What is the function of Root Face?
Ans. To remove excess heat and act as a heat sink.