2. Shielded Metal Arc Welding (SMAW)

3. SMAW Electrode Classification Example E7018 E indicates electrode 70 indicates 70,000 psi tensile strength 1 indicates use for welding in all positions 8 indicates low hydrogen E7018-A1-H8R

4. ANSI/AWS - 5.1 : Specification for Covered Carbon Steel ANSI/AWS - 5.5 : Specification for Low Alloy Steel ANSI/AWS - 5.4 : Specification for Corrosion Resistant Steel AWS Website: http://www.aws.org

5. Coating Materials - Partial List Arc Stabilizers Titania TiO 2 Gas-Forming Materials Wood Pulp Limestone CaCO 3 Slag-Forming Materials Alumina Al 2 O 3 TiO 2 SiO 2 Fe 3 O 4 Slipping Agents to Aid Extrusion Clay Talc Glycerin Binding Agents Sodium Silicate Asbestos Starch Sugar Alloying and Deoxidizing Elements Si, Al, Ti, Mn, Ni, Cr

6. Linnert, Welding Metallurgy AWS, 1994

7. Linnert, Welding Metallurgy AWS, 1994

8. SMAW Advantages Easily implemented Inexpensive Flexible Not as sensitive to part fit-up variances Shielded Metal Arc Welding

9. Advantages Equipment relatively easy to use, inexpensive, portable Filler metal and means for protecting the weld puddle are provided by the covered electrode Less sensitive to drafts, dirty parts, poor fit-up Can be used on carbon steels, low alloy steels, stainless steels, cast irons, copper, nickel, aluminum

10. Quality Issues Discontinuities associated with manual welding process that utilize flux for pool shielding –Slag inclusions –Lack of fusion Other possible effects on quality are porosity, and hydrogen cracking Shielded Metal Arc Welding

11. Limitations Low Deposition Rates Low Productivity Operator Dependent Shileded Metal Arc Welding

12. Other Limitations Heat of welding too high for lead, tin, zinc, and their alloys Inadequate weld pool shielding for reactive metals such as titanium, zirconium, tantalum, columbium