CWB 2 Module 7 Questions and Answers Rated A+

CWB 2 Module 7 Questions and Answers Rated A+ True or False? Weld metal shrinkage is not proportional to the amount of weld metal. False True or False? Longitudinal residual stress may be as high as the yield stress of the base metal. True True or False? There is no residual stress in a steel plate with mill rolled edges without any additional head treatment False True or False? Oxy-fuel gas cutting along rectangular steel plates always causes distortion. False What is the following formula applicable to? S = 0.18 Aw / t + 0.05d Transverse shrinkage - butt welds What is the following formula applicable to? S = 0.025 Aw / Ar Longitudinal shrinkage - butt welds In seam welding, what is the simplest form of distortion control? Start at the same distance from the end of the joint, making a short weld first True or False? Where planting and stiffeners are combined as a ship bulkhead work, the butt and seam welds in plating should be welded before the stiffeners. True True or False? In filling up a weld joint, the number of weld passes does not affect distortion. False True or False? Arc travel speed does not affect the amount of distortion. False True or False? The heat distribution around the welding arc is the same regardless of its travel speed. False Distortion may be partially or fully controlled by mechanical means using: A) Rigid clamping or fixturing B) Pre-bending or setting C) Pre-weld heat treatment D) Post-weld heat treatment E) Subassembly F) A, B, and C F) A, B, and C True or false? In a welded assembly with both groove and fillet welds, the fillet welds should be completed first and then the groove welds. False What is the advantage of intermittent fillet welds? Less distortion What is the advantage of using sub-assemblies when feasible? Reduces cumulative tolerances, easy to handle for large structures True or False? Balancing welds about the neutral axes can reduce distortion. True True or False? Reducing the root opening of a groove joint can reduce shrinkage. True Is rigid alignment and complete joint restraint by strongbacks, clamps, and similar devices a recommended practice? No True or False? Excessive root face in plate edge preparation should be avoided True The contraction effects in the weld metal that are of greater magnitude and, therefore, more serious are: A) Longitudinal B) Transverse B) Transverse What is the maximum temperature in heat straightening or forming of low alloy steels? 650°C True or False? When a heated member cools non-uniformly, the portions that cool first go into compression and the portions that cool last, go into tension. True True or False? In flame forming, if the temperature is much higher than 650°C it can cause damage to the base metal. True In flame straightening, if the temperature if too low the member will not be straightened. Why? Insufficient to produce upsetting In flame straightening or forming of low alloy steel members, what colour should be watched for? A dull or cherry red colour