Intro to Arc Welding Techniques WELD 105 Northampton

Intro to Arc Welding Techniques WELD 105 Northampton Community College

Orientation �Introduction & Registration �Student Information Sheet �Syllabus �Attendance with Gas log �Student Behavior �Assigned Work Spaces �Fire Extinguisher Location

Student Responsibilities �Safety �Cheating & Plagiarism �House Cleaning �Economical Use of Materials �Personal Protective Equipment (PPE) �Lab Modules Reading �First Aid �Text Book Reading �Homework

Job of a Welder

Writing Assignments �Use a Computer �Use a ruler for Sketches �Identify a Specific Problem �Detail the Solution / Corrective Action

Personal Welding Safety �Eyes �Foreign Objects – Grinding, Slag Removal, Wire Brushing/Cutting �Ultraviolet Rays – Short Term – Arc Flash (Cornea Sun Burn) �Infrared Rays – Long Term – Cataracts �Skin �Ultraviolet Rays – Short Term – 1 st thru 3 rd degree burns �Infrared Rays – Long Term – Skin Cancer

Personal Welding Safety �Lungs �Fumes � Short Term � Tightness in Chest - Smoke � Metal Fume Fever - Zinc � Long Term � Emphysema �Electric Shock

Fire Types �Class A – Combustibles like paper, wood, etc. �Use water to extinguish �Class B – Oil and Grease �Use foam or dry chemical to extinguish �Class C – Energized Electrical �Use dry chemical to extinguish �Class D – Metal such as magnesium, titanium, etc. �Use foam to extinguish

Portable Grinder Safety �Eyes – Safety glasses and Clear Face Shield �Lungs – Dust mask for grinder and metal particles �Ears – Hearing protection �Hands – Gloves or not? �Equipment �Rating and type of wheel �Condition of electric cord �Guard(s) in place

Fusion vs. Non-Fusion Welding �Fusion Welding – The melting together of base metal and filler metal. �Non-Fusion Welding – The base material is heated but not melted. �Read Chapter 1 in Text Book

AWS Welding Process Definition �Fusion or Non-Fusion �Source of Heat �With or Without Filler Metal �Source of Shielding Gas �With or Without Mechanical Pressure �Mode of the Process (Manual, Semi-Auto, Mechanized)

Amperage vs. Voltage �Voltage is the “driving force” in an electrical circuit or the pressure in a water piping system “pressure”. �Voltage is also called “potential”. �Amperage is the “flow” of electrons in an electric circuit and the “flow” or “movement” of water in a pipe or hose. �How is amperage controlled in the SMAW process? �How is voltage controlled in the SMAW process?

Welding Machine Nameplate Information �Manufacturer’s Name �Brand Name or Nickname of the Power Source �Serial Number �Model Number �Duty Cycle �Primary Voltage Requirements �Primary current Requirements �Secondary Current Output at Rated Capacity & Dead Short �Secondary Voltage Output at Rated Capacity (Load Voltage) �Arc Voltage �Open Circuit Voltage (OCV) �Phase of Power Source

Types of Welding Current �Alternating Current (AC) �Combination of Direct Current Straight & Reverse pol. �Direct Current �Straight Polarity (DCEN, DCSP, DC-) � Senators – SEN – Straight Electrode Negative � 70% of available heat is concentrated at the workpiece �Reverse Polarity (DCEP, DCRP, DC+) � Representatives – REP – Reverse Electrode Positive � 70% of available heat is concentrated at the electrode

Types of Welding Power Sources �Static Power Sources �Transformer with AC output �Transformer / rectifier with DC output only �Transformer / rectifier with AC & DC output �Rotating Power Sources �Motor Generator – Electric, Gas, Diesel, Propane �AC only, DC only, or AC & DC output

Parts of a Fillet Weld 1 2 5 4 3

Types of Throat Actual Throat Effective Throat Theoretical Throat

Types of Weld Defects