حكاكي ليزري لوله هاي گازي API جهت رديابي محصول

چكيده انگليسي :

Laser Marking of API Pipes for Tracking Products Saeed Taghiyar s taghiyar@me iut ac ir Date of Submission 21 September 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohsen Badrossamay mohsen badrossamay@cc iut ac ir Ehsan Foroozmehr eforoozmehr@cc iut ac irAbstract Gas pipelines need to be traced due to the sensitive usage and the number of involved companies In presentresearch the use of laser engraving for marking API pipes is investigated Through an automatic process thismethod of marking creates durable and high quality marks For this purpose related standards have beenreviewed to obtain the maximum allowable groove depth on the pipes After ensuring the acceptance of theprocess in the standards initial samples have been engraved to find the appropriate laser characteristics required to have adequate material removal and visible mark on the test pieces The Taguchi method is usedto design the experiments of laser engraving process with different parameters and to determine the effect ofeach one on the process All experiments have been done with 80 W pulsed Nd YAG laser with a pulse widthof 1 s Analyses are performed for two simultaneous outputs in order to reach the deepest engraving in theshortest time To validate the results some samples are engraved with optimized parameters The resultsadmitted the optimized condition predicted via Taguchi method The effect of each parameter on the depth ofengraving and the process time were also analyzed and it was found that the laser power is the most effectiveparameter In order to control the material structure and its properties after the process metallography hardness and tensile tests were performed Although there is a small change in the properties of the originalmaterial the results satisfied standard s requirements Consequently the absence of heat affected zone HAZ at the laser engraved region was observed Simulation of laser engraving is also performed in Abaqus Explicit For the modeling of materialevaporation during the process element deletion is considered In this research by using several subroutineslike VUMAT VUAMP and VUSDFLD and a Python based program in addition to defining a non uniformheat flux in Abaqus Explicit elements are deleted as soon as they exceed the boiling temperature One pulseof laser is simulated through an axisymmetric model to investigate the temperature field in engraved region The simulation was verified based on a previous job and then used to predict the temperature field in thecurrent research The results show that the pulse duration is so small that the temperature reaches the ambienttemperature shortly after each pulse Therefore there is no heat accumulation during the process Theabsence of HAZ in the experiments was also concluded based on the simulation results Keywords Laser engraving API pipes Taguchi Abaqus Explicit non uniform heat flux elementdeletion

تقي يار، سعيد

حكاكي ليزري لوله هاي گازي API جهت رديابي محصول

تاگوچي , Abaqus/Expicit , شار غير يكنواخت , حذف المان