Assessing the impact of sequencing laboratory welding practicums.

摘要

The effects of mastering 1F (flat position-fillet) welds on carbon steel using a sequenced pattern of welding was examined. Participants ( N = 71) were randomly assigned a specific sequence of welding between Gas Metal Arc Welding (GMAW) and Shielded Metal Arc Welding (SMAW). The hypothesis of teaching beginning welders the GMAW process before the SMAW process to improve the ability to master American Welding Society (AWS) welds was tested. A welding pretest was administered to determine any prior welding knowledge. Sixty minutes of welding instruction taught proper welding safety, machine set-up, arc length, travel speed, work angle, and correct bead formation. Two practice sessions of 60 minutes were given for participants to become familiar with each welding process, followed by two testing sessions of ten minutes. During the testing period, individuals were assessed on their ability to produce an AWS 1F (flat position- fillet) lap weld in a given sequence. Welds were graded according to the AWS rubric for fillets with a total of four criteria categories based on the following criteria: a) presence of cracks or porosity, b) complete fusion, c) fillet leg size is specified minimum, and d) undercut - not to exceed 1/32 inches. The study indicate that students perform welds that meet AWS quality standards when using the GMAW process, however, the results were not statistically significant.