exam question - Paper 1 Flashcards
Describe in detail how a Charpy Impact test is carried out?
the test is usually carried out, when a notch specimen is broken by a swinging hammer and the amount of energy required to break the specimen is recorded.
draw and label charpy v notch test
draw and label a typical curve from c/s sample indicating the meaning of this results (charpy v notch)
Explain CTS test
The CTS Test consists of two plates, one square and the other rectangular. The square plate, 3” on a side, is fastened by a ½” bolt through its centre to the rectangular plate and anchored by welding.
The test weld at the right side of the specimen is called the bithermal weld because the plates supply two paths for heat flow, one in each plate.
The test on the left side is called the trithermal weld since heat can flow in one direction in the top plate and in two directions in the bottom plate, or a total of three paths.
The contacting surfaces are ground before assembly to ensure efficient heat flow.
After the specimen is assembled and has cooled to room temperature, the bithermal weld is deposited,
, the specimen is all allowed to re – cool and the trithermal weld is deposited.
After a hold for 72 hours at room temperature, the degree of cracking is determined by measuring the crack length of three metallographic specimens cut from cross – sections of the weld.
draw CTS test
Discuss Brittle Fracture
no warning signs
appearance smooth
shape - chevron shape
low temp
without going through significant deformation
Discuss Ductile Fracture
more warning signs
appearance rough
shape - cup cone
high temp
undergoes significant deformation
Discuss fatigue
Fatigue cracks tend to start at a discrete point or line where stress is concentrated. This may be a weld toe on a fillet weld, weld root a weld direct. The fracture surface is usually marked in bands called “Beach marks” that indicate progress of the crack from the crack initiation.
List 10 important items relating only to heat treatment
- Heating rate
- Soaking time
- Cooling rate
- Soaking Temperature
- Heating band
- Soaking band
- Insulation band
- Thermo couple placements
- Heating time
- Cooling time
List 2 problems which can result of welding from the following materials?
Austenitic S/s
Nickel and nickel alloys
Aluminum and alloys
Austenitic S/s = Carbide precipitation, Hot Cracking
Nickel and nickel alloys= Carbide precipitation, Cold Cracking
Aluminum and alloys = hot Cracking, over aging, Distortion
Briefly discuss the following headings :iso 3834-2
Contract and Design Review
Welding Personal
Equipment
Welding Consumables
Welding Inspection and testing
Contract and Design Review
Manufacturer shall review all contractual requirements and technical data provided by the user to ensure that all information required to carry out the manufacturing is available and complete prior to commencing work. This is to ensure the manufacturer is capable to meet the requirements of the user or purchaser and to ensure adequate planning for all quality related activities.
Welding Personal
Manufacturers shall have at their disposal sufficient resources for planning, performing and supervising production welding. Only qualified personnel shall be used for performance of welding and this shall be proven by an appropriate test. In addition manufacturers shall have welding coordination personnel who are responsible and posses authority to take action.
Equipment
Manufacturers shall have adequate, suitable, calibrate / validated equipment at their disposal for performing of manufacturing activities. In addition Manufacturers shall have workshop capacity for such equipment.
Welding Consumables
Manufacturers shall have adequate personal and procedures responsible for the control of welding consumables, the procedures shall indicated storage and handling requirements to avoid damage, oxidization and moisture pick of consumables. All procedure will be as per supplier recommendation.
Welding Inspection and testing
Manufacturers shall implement appropriate points in the manufacturing process to ensure inspection and tests are performed before, during and after welding during the manufacturing process.
Briefly discuss the following headings : Asme Vii Div 1
Authority and Responsibility
Material Control
Correction of non Conformance
NDT
Calibration AND Measurment of testing equipment
List 5 Particulars on a data Plate of a pressure Vessel
*Design Temp
*Design Pressure
*Manufacture Name
*Date of fabrication
*Code of Contraction
* Equipment number
Describe how a nick break test is carried out?
- Prepare the sample: Cut a small sample from the material to be tested.
- Clean the sample: Clean the sample surface to remove any dirt, oil, or other contaminants.
- Apply nickel nitrate solution: Apply a few drops of nickel nitrate solution to the cleaned surface.
- Heat the sample: Heat the sample in a Bunsen flame or oven to around 800-900°F (427-482°C) for about 5-10 minutes.
- Quench the sample: Quench the sample in water or oil to rapidly cool it.
- Break the sample: Break the sample using a hammer or press.
- Examine the fracture surface: Examine the fracture surface for signs of sulfur presence
Revealed Defects:
Porosity
Lack of penetration
Lack of Fusion
Sal inclusions
What’s the Purpose of a WPS
WPS is a written qualified welding procedure prepared to provide direction for making production welds to Code requirements.
