LESSON 1- INTRODUCTION TO THE BASIC OF WELD.pptx

Introduction of the basic welding

1. OBJECTIVES To introduce the basics of welding To provide an overview of different welding processes and their applications To develop an understanding of safety precautions and equipment used in welding.

2. Welding is the process of joining metal pieces by heating them to suitable temperature that cause them to melt and fuse together into a single piece. WHAT IS WELDING?

3. WELDING INVOLVES THE USE OF FOUR COMPONENTS:.

4. METAL

5. HEAT SOURCE

6. FILLER METAL

7. SHIELDING GAS

8. The metals are heated to their melting point while being shielded from the air, and then a filler metal is added to the heated area to produce a single piece of metal. It can be performed with or without filler metal and with or without pressure.

9. DIFFERENT PROCESS OF WELDING

10. SHIELDED METAL ARC WELDING GAS METAL ARC WELDING FLUX-CORED ARC WELDING GAS TUNGSTEN ARC WELDING OXYGEN- ACETYLENE WELDING SUBMERGED ARC WELDING

11. SHIELDED METAL ARC WELDING GAS METAL ARC WELDING FLUX-CORED ARC WELDING GAS TUNGSTEN ARC WELDING OXYGEN- ACETYLENE WELDING SUBMERGED ARC WELDING

12. SHIELDED METAL ARC WELDING GAS METAL ARC WELDING FLUX-CORED ARC WELDING GAS TUNGSTEN ARC WELDING OXYGEN- ACETYLENE WELDING SUBMERGED ARC WELDING

13. SHIELDED METAL ARC WELDING GAS METAL ARC WELDING FLUX-CORED ARC WELDING GAS TUNGSTEN ARC WELDING OXYGEN- ACETYLENE WELDING SUBMERGED ARC WELDING

14. SHIELDED METAL ARC WELDING GAS METAL ARC WELDING FLUX-CORED ARC WELDING GAS TUNGSTEN ARC WELDING OXYGEN- ACETYLENE WELDING SUBMERGED ARC WELDING

15. SHIELDED METAL ARC WELDING GAS METAL ARC WELDING FLUX-CORED ARC WELDING GAS TUNGSTEN ARC WELDING OXYGEN- ACETYLENE WELDING SUBMERGED ARC WELDING

16. PARTS OF A SMAW WELDING MACHINE

17. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL

18. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE

19. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP

20. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/ CABLE

21. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/CABLE ELECTRODE HOLDER

22. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/CABLE ELECTRODE HOLDER ELECTRODE

23. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/CABLE ELECTRODE HOLDER ELECTRODE ELECTRODE LEAD/CABLE

24. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/CABLE ELECTRODE HOLDER ELECTRODE ELECTRODE LEAD/CABLE PLUG TO POWER SOURCE

25. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/CABLE ELECTRODE HOLDER ELECTRODE ELECTRODE LEAD/CABLE PLUG TO POWER SOURCE POWER SWITCH

26. PARTS OF A SMAW WELDING MACHINE WORK PIECE OR BASE METAL WELDING TABLE EARTH CLAMP WORKPIECE LEAD/CABLE ELECTRODE HOLDER ELECTRODE ELECTRODE LEAD/CABLE PLUG TO POWER SOURCE POWER SWITCH CURRENT CONTROL HANDLE

27. DIFFERENT TYPES OF WELDING MACHINE

28. TRANSFORMER TYPE (AC WELDING MACHINE) A welding machine that uses Alternating Current as power supply. AC is a kind of electricity which reverses its direction periodically for 60 cycle current, the current that goes in one direction and then in the other direction 60 times in the same second, so that the current change its direction 120 times in 1 second.

29. RECTIFIER TYPE (DC WELDING MACHINE) This welding machine uses direct current as power supply. Direct Current is an electricity that flows in one direction, and it has a constant current.

30. INVERTER TYPE (AC/DC WELDING MACHINE) This welding machine uses an AC-DC as a power supply. These designs are known as inverter welding units. They generally first rectify the utility AC power to DC; then they switch (invert) the DC power into a stepdown transformer to produce the desired welding voltage or current. The switching frequency is typically 10 kHz or higher.

31. GENERATOR TYPE- DIESEL/GASOLINE ENGINE DRIVEN WELDING MACHINE Welding generators are equipped with a diesel/gasoline engine which converts mechanical energy to electrical energy. Welding Generator and welding rectifiers are the portable type machines which is used with AC input and provides desired DC output.

32. Shielded metal arc welding (SMAW) also known as manual metal arc welding (MMA or MMAW), or informally as stick welding, is a manual arc welding process that uses a consumable electrode covered with a flux to lay the weld. SMAW

33. An electric current, in the form of either alternating current or direct current from a welding power supply, is used to form an electric arc between the electrode and the metals to be joined. The workpiece and the electrode melts forming a pool of molten metal (weld pool) that cools to form a joint. As the weld is laid, the flux coating of the electrode disintegrates, giving off vapors that serve as a shielding gas and providing a layer of slag, both of which protect the weld area from atmospheric contamination.

34. ADVANTAGES Versatile- readily applied to a variety of applications and a wide choice of electrodes. Relatively simplicity and portability of equipment. Low cost Adaptable to confined spaces and remote locations. Suitable for almost all welding positions like flat, horizontal, vertical and overhead. Convenient

35. ADVANTAGES Versatile- readily applied to a variety of applications and a wide choice of electrodes. Relatively simplicity and portability of equipment. Low cost Adaptable to confined spaces and remote locations. Suitable for almost all welding positions like flat, horizontal, vertical and overhead. Convenient

36. ADVANTAGES Versatile- readily applied to a variety of applications and a wide choice of electrodes. Relatively simplicity and portability of equipment. Low cost Adaptable to confined spaces and remote locations. Suitable for almost all welding positions like flat, horizontal, vertical and overhead. Convenient

37. ADVANTAGES Versatile- readily applied to a variety of applications and a wide choice of electrodes. Relatively simplicity and portability of equipment. Low cost Adaptable to confined spaces and remote locations. Suitable for almost all welding positions like flat, horizontal, vertical and overhead. Convenient

38. ADVANTAGES Versatile- readily applied to a variety of applications and a wide choice of electrodes. Relatively simplicity and portability of equipment. Low cost Adaptable to confined spaces and remote locations. Suitable for almost all welding positions like flat, horizontal, vertical and overhead. Convenient

39. ADVANTAGES Versatile- readily applied to a variety of applications and a wide choice of electrodes. Relatively simplicity and portability of equipment. Low cost Adaptable to confined spaces and remote locations. Suitable for almost all welding positions like flat, horizontal, vertical and overhead. Convenient

40. DISADVATAGES Not as productive as continuous wire process (MIG) Likely to be more costly to deposit a given quantity of metal. Frequent stop/ starts to change electrode. Relatively high metal wastage (electrode stubs) Current limits are lower than for continuous or automatic processes.

41. DISADVATAGES Not as productive as continuous wire process (MIG) Likely to be more costly to deposit a given quantity of metal. Frequent stop/ starts to change electrode. Relatively high metal wastage (electrode stubs) Current limits are lower than for continuous or automatic processes.

42. DISADVATAGES Not as productive as continuous wire process (MIG) Likely to be more costly to deposit a given quantity of metal. Frequent stop/ starts to change electrode . Relatively high metal wastage (electrode stubs) Current limits are lower than for continuous or automatic processes.

43. DISADVATAGES Not as productive as continuous wire process (MIG) Likely to be more costly to deposit a given quantity of metal. Frequent stop/ starts to change electrode . Relatively high metal wastage (electrode stubs) Current limits are lower than for continuous or automatic processes.

44. DISADVATAGES Not as productive as continuous wire process (MIG) Likely to be more costly to deposit a given quantity of metal. Frequent stop/ starts to change electrode . Relatively high metal wastage (electrode stubs) Current limits are lower than for continuous or automatic processes.