Welding Technology Practical Utilizing - Assignment Example

ASSIGNMENT TITLE: Using information and preparing for Work ASSIGNMENT No: 2 UNIT TITLE: Welding Technology Unit No. 23 Ref No. R/600/0274 I confirm that this assignment is ‘Fit for Purpose’. Verifier’s Signature: Name: R Chase Date Approved: Assessor/Lecturer: A R Fisher Assignment Author: A R Fisher Learner’s Name: Course Code: OUTCOME 2: Be able to prepare for welding operations (See Guidance notes for details) ASSESSMENT CRITERIA: In order to pass this assignment, the evidence that the learner presents for assessment needs to demonstrate that they can meet all of the learning outcomes for the assignment. INDICATIVE READING FOR LEARNERS BTEC Indicative Reading: Davies A C — Science and Practice of Welding, Volume 1 (Cambridge University Press, 1993) ISBN 052143565X Davies A C — Science and Practice of Welding, Volume 2 (Cambridge University Press, 1993) ISBN 0521435668 Smith B — Welding Practice (Butterworth-Heinemann, 1995) ISBN 0340614064 Timings R — Fabrication and Welding Engineering (Newnes, 2006) ISBN 0750666919 Weekly Teaching Scheme Week Launch – w/c Week 7 Topics within this outcome Hand in – Week 13 7 Launch Assignment 2 & 3: Provide overview of assignments 2 and 3. Discuss the documentation and what is required for assignment. Explain the quality requirements for the test pieces 8 Welding Procedures: Learners to research and discuss the following questions. What is a welding procedure? Why are they used? What are the welding parameters that can be measured Demonstrate writing a procedure and then give them a task at establishing welding parameters for a set test piece 9 Selecting Welding Consumables: Learners to research and discuss the following questions. What factors determine consumable selection? Discuss information sources for consumable selection and parameter selection 10 Welding Parameters: Learners to research and discuss the following questions. What are the welding parameters that can be measured? Discuss the effects on the weld of selecting incorrect welding parameters. (presentation) 11 Arc monitoring: How to use the arc monitor to record welding parameters to write a weld procedure sheet. 12 Assignment Support 13 Assignment Collection and support (Last Chance!) In order to pass this assignment, the evidence that the learner presents for assessment needs to demonstrate that they can meet all of the following pass grades. Grading Criteria. Unit 23 Evidence Sought P2 Use information sources to select a welding process for a given application, and suggest suitable parameters for the welding process Clear description of Information sources used for setting up equipment, equipment used and safety issues. P3 Produce a list of consumables that are required for a selected welding process Complete work Plan and Welding Specification P4 Plan the tools and equipment needed to produce welded components safely using a selected welding process Complete work Plan and Welding Specification M1 Analyse the effect of using incorrect welding parameters for a selected welding process including the effects on quality and safety when producing welded components Answer to relevant questions on assignment SCENARIO: This assignment is aimed at preparing for the practical welding in Assignment 3 TASKS: In Assignment 3 you will have to complete the welds shown below. For this assignment (2) you will need to - i) Select a welding process for part 1 (either MIG or MMA) (P2a) ii) Produce a work plan and welding procedure sheet for each joint. (P3, P4) iii) Include a list of information sources you have used (P2b) iv) Answer part 3 (M1) 1. The following samples are to be welded in 3 mm plain carbon steel A. Bead on plate in the flat position. This is an MIG. To make a suitable bead on plate in the flat position, it is important to maintain the welding plate surface higher than the molten puddle. Adjustment of the welding torch ought to be done in order to produce the proper kind of flame for the metal undergoing welding (Mark B & Bowditch W, 2009) The beads are made through raising or lowering the welding flare while slightly moving in a circular way while making forward progress. The tip then forms an angle of about 45 degree with the plate surface. Finally, the flame points within the welding direction. The welding speed is reduced or the angle between the tilt and the plate surface is increased in order to increase the depth of fusion. A proper bead weld is normally lower than the upper surface of the plate (Mark B & Bowditch W, 2009). Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Tacking Welding Deslagging Testing B. Lap fillet in the horizontal vertical position This is an MIG. The electrodes are held in a manner that an angle of approximately 30 degrees is formed from the vertical and the inclination is 15 degrees within the welding direction. The weaving motion is similar like in the tee joint but in this case the gap at the edge of the top plate is adequately long in order to ensure good fusion devoid of undercut (Woodhead Publishing, 1999). In lap joints for heavier plates, to make them it is necessary to deposit a series of stringer beads. When making lap joints on plates whose thickness vary, the electrode should be held in a manner that an angle of 20-30 degree is formed from the vertical. However, one should be careful to ensure that there is no overheat/undercut for the thinner plate edge (Mark & Bowditch, 2009). For a lap joint to be produced, with appropriate shape, the pointing of the electrodes need to be towards the weld at angle of approximately 30-40 degrees using the horizontal plane. A fillet lap will then have a convex shape as a result of fast solidification of the weld-bead. It is possible to make the size-of a fillet within a single run, although this will be dependent on the electrode’s diameter as well as the thickness of the plates undergoing welding (Mark & Bowditch, 2009). For instance, a fillet lap weld that is between two lapped plates, whose thickness is between 6-8mm, can be deposited within 1, 2 or 3 passes. The sole-pass lap fillet weld using weaving movement in order to ensure there is a completion of the weld within a single pass along the joint. Furthermore, for the two-pass fillet weld, depositing of the initial bead is done as a strong bead through straight down movement down the joint devoid weaving. Finally, for the 3rd lap-fillet, the initial bead is a string bead that is deposited within the angle that is produced between the 1st and the 2nd plate (CWB Group, 2001). Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Tacking Welding Deslagging Testing C. Tee Fillet in the flat position This is an MIG. In the above joint, the fillet increments in one line are staggered when compared to the other line. The arc is kept short and moved at definite speed rate. Generally, the MIG gun is positioned straight down to leaning toward the direction of the weld up to 35 degrees. A high voltage setting is used (Woodhead Publishing, 1999). The electrode angle is supposed to be approximately 30 degree. Two or more passes are needed for a high quality weld. The thinner electrode is utilized for the initial bead and the final runs follows using thicker electrodes. Each run should be effectively deslagged prior to laying the next run. Two plates should be tack to make the Tee joint as well as set the angle of 45 degrees to the horizontal position. The weld metal should enter and fuse into the joint’s corner and there should be no under-cutting with equivalent leg length. The weld is created using the electrode at an angle of approximately 70 degree to the line of welding curve motion (Mark & Bowditch, 2009). Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Job setting Tacking Welding Deslagging Testing D. Tee Fillet in the horizontal / vertical When the tee joint is made using a horizontal position, the two plates are located at right angles to each other, forming an inverted T.A fillet weld is utilized to make the tee joint. A short arc is required in order to offer good fusion at the root of the weld. The electrode is held at an angle of 45 degrees to the surfaces of the plate using an inclination of about 15 degrees in the welding direction (Mark & Bowditch, 2009). Tee-fillet made using a horizontal position, the electrode is supposed to be approximately 30 degrees. Two or more passes will be needed for a high quality weld. For the thick section, a thinner bead should be utilized for the first bead and then the thicker electrodes should follow. Two plates are tack welded in order to produce a Tee joint and are normally set at 45 degree to the horizontal position. The weld metal should infiltrate and fuse into the joint’s corner. The electrode at an angle of approximately 70 degree is used to make the weld (Mark & Bowditch, 2009). Welding of heavier plates might necessitate several passes where the second layer is made using semi-circular weaving motion. To make sure that there is good fusion and undercut-ting is prevented, a slight pause at the end of every weave is made. Staggered intermittent fillet are appropriate if the tee joints are long. In addition, intermittent welds result to decreased warpage as well as reduced distortion (CWB Group, 2001). Work plan Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Job setting Tacking Welding Deslagging Testing D. Open corner weld in the flat position This is an MMA. The fitting of the members is done as shown by the above figure. A V-shaped groove is left where the fillet weld is deposited. Fusion ought to be complete in order to ensure that there is full metal thickness. In generally, it is essential for a light overlap on the corner. Even though setting up the overlap is a problem, using the overlap assists penetration at the root. In addition, the overlap should be maintained at a minimum (1.0–2.5 mm) because the gap prevents absolute penetration at the root. For a joint tack weld using open corner weld, two plates along with the appropriate gap between them and an angle of 90 degrees between the plates produce a right-angled corner joint. Following the de-slagging of the initial run, the 2nd and 3rd runs are made using electrodes at an angle of approximately 70-75 degree utilizing a slight weave movement. If necessary, it is suitable to make a sealing run on the base. The slag should be removed prior to depositing any more beads, to have a total penetration and correct fusion (CWB Group, 2001) Work plan Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Job setting Tacking Welding Deslagging Testing 2. You will be required to produce the following welded test pieces in 1.6mm thick plain carbon steel using the spot welding process. (P7, P8) A. Lap Joint mm B. Flange Butt weld 3. a) List the welding parameters associated with both the MIG and MMA welding processes. Amperage, voltage, gas flow, welding speed, arc length etc b) Analyse the effect on quality and safety that the incorrect setting of each would have on the finished welding component. (M1) Finished welding component Effect on quality and safety of the incorrect setting Bead on plate in the flat position Improper Weld Bead Profile, Weld porosity Lap fillet in the horizontal vertical position Lack of Fusion, Improper Surface Conditions Tee Fillet in the flat position Lack of Fusion, Weld porosity Tee Fillet in the horizontal / vertical Improper Surface Conditions Open corner weld in the flat position Faulty wire delivery allied to equipment set-up and maintenance. References CWB Group, 2001, Fundamentals of Welding Technology, Sydney: CWB Group. Mark B & Bowditch W, 2009, Welding Technology Fundamentals, New York: Goodheart-Willcox Publisher. Woodhead Publishing, 1999, Exploiting Advances in Arc Welding Technology, London Woodhead Publishing, Read More

Finally, for the 3rd lap-fillet, the initial bead is a string bead that is deposited within the angle that is produced between the 1st and the 2nd plate (CWB Group, 2001). Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Tacking Welding Deslagging Testing C. Tee Fillet in the flat position This is an MIG. In the above joint, the fillet increments in one line are staggered when compared to the other line. The arc is kept short and moved at definite speed rate.

Generally, the MIG gun is positioned straight down to leaning toward the direction of the weld up to 35 degrees. A high voltage setting is used (Woodhead Publishing, 1999). The electrode angle is supposed to be approximately 30 degree. Two or more passes are needed for a high quality weld. The thinner electrode is utilized for the initial bead and the final runs follows using thicker electrodes. Each run should be effectively deslagged prior to laying the next run. Two plates should be tack to make the Tee joint as well as set the angle of 45 degrees to the horizontal position.

The weld metal should enter and fuse into the joint’s corner and there should be no under-cutting with equivalent leg length. The weld is created using the electrode at an angle of approximately 70 degree to the line of welding curve motion (Mark & Bowditch, 2009). Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Job setting Tacking Welding Deslagging Testing D. Tee Fillet in the horizontal / vertical When the tee joint is made using a horizontal position, the two plates are located at right angles to each other, forming an inverted T.

A fillet weld is utilized to make the tee joint. A short arc is required in order to offer good fusion at the root of the weld. The electrode is held at an angle of 45 degrees to the surfaces of the plate using an inclination of about 15 degrees in the welding direction (Mark & Bowditch, 2009). Tee-fillet made using a horizontal position, the electrode is supposed to be approximately 30 degrees. Two or more passes will be needed for a high quality weld. For the thick section, a thinner bead should be utilized for the first bead and then the thicker electrodes should follow.

Two plates are tack welded in order to produce a Tee joint and are normally set at 45 degree to the horizontal position. The weld metal should infiltrate and fuse into the joint’s corner. The electrode at an angle of approximately 70 degree is used to make the weld (Mark & Bowditch, 2009). Welding of heavier plates might necessitate several passes where the second layer is made using semi-circular weaving motion. To make sure that there is good fusion and undercut-ting is prevented, a slight pause at the end of every weave is made.

Staggered intermittent fillet are appropriate if the tee joints are long. In addition, intermittent welds result to decreased warpage as well as reduced distortion (CWB Group, 2001). Work plan Tools Arc welding machine Hand grinder Materials Electrode Pieces of M/S flat Activities Marking Cutting Cleaning Job setting Tacking Welding Deslagging Testing D. Open corner weld in the flat position This is an MMA. The fitting of the members is done as shown by the above figure.

A V-shaped groove is left where the fillet weld is deposited. Fusion ought to be complete in order to ensure that there is full metal thickness. In generally, it is essential for a light overlap on the corner. Even though setting up the overlap is a problem, using the overlap assists penetration at the root. In addition, the overlap should be maintained at a minimum (1.0–2.5 mm) because the gap prevents absolute penetration at the root. For a joint tack weld using open corner weld, two plates along with the appropriate gap between them and an angle of 90 degrees between the plates produce a right-angled corner joint.

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