Page 37 - CITS - Welder - Trade Theory
P. 37

WELDER - CITS



              d  Kelvin Scale–The degree is used to measure this scale K°. It range from 273.15° to 373.15°K


















                    Formula and relation of centigrade , Fahrenheit , and Kelvin

           Introduction
                                     C       F-32      R          K-273.15
                                          =        =          =
                                    100      180       80          100


            Principle of arc welding and characteristics of arc


           Objectives: At the end of this lesson you shall be able to
           •  state the electric arc welding
           •   state the principal of arc welding
           •  state the characteristics of Arc.



           Electric arc welding
           This is a process of welding in which the heat energy is obtained from electricity. When electric current passes
           through a medium material it generates heat.
           An electric arc maintained between the end of a coated material electrode and work piece.
           The Flux covering melts during welding and forms gas and slag the arc molten pool.
           Flux also prevent the atmosphere contamination oxidation (oxygen & nitrogen)
           The flux also provides a method of adding deoxidizer and alloying elements to the weld metal.





























                                                           24

                                           CITS : C G & M - Welder - Lesson 6&7                                                                                   CITS : C G & M - Welder - Lesson 6&7
   32   33   34   35   36   37   38   39   40   41   42