tailieunhanh - Arc Welding 2011 Part 11

Tham khảo tài liệu 'arc welding 2011 part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Corrosion Fatigue Behaviour of Aluminium 5083-H111 Welded Using Gas Metal Arc Welding Method 191 Element Al Mg Mn Fe Si Cr Cu Zn Ti Others total ER4043 Balance Not specified Be ER5183 Balance Not specified ER5356 Balance Be Table 9. Typical chemical compositions of filler wires percentage by mass single values represent minimum levels . 5083-H111 aluminium plates were welded in horizontal position using argon shielding gas. The welding parameters were selected to ensure a spray transfer mode for all the welds and are given in Table 10. Parameters Arc voltage Welding current Wire feed rate Wire diameter Nozzle to plate distance Travel speed Torch angle Gas flow rate Unit V A m min m m mm m min Degrees l m in SA- GMAW 24-29 133-148 15-20 60-80 18-33 FA- GMAW 20-23 133-148 15-20 60-80 19-28 Table 10. Measured pulsed gas metal arc welding process parameters. Material characterization In order to analyse the aluminium samples and to quantify the material properties that may influence fatigue resistance the microstructures of the as-machined and as-welded specimens were analysed the hardness was measured and tensile tests were performed. The corrosion resistance in NaCl solution was evaluated using immersion testing. Microstructural analysis As-supplied and as-welded samples were sectioned and machined to produce rectangular fatigue and tensile specimens with dimensions shown schematically in Figure 7. Samples were removed for microstructural examination in the long transverse LT direction longitudinal LD direction and short transverse ST direction Figure 7 . Samples were prepared for microstructural analysis and etched using Keller s reagent as described in ASTM standard E340 17 . The metallographic samples were examined with an inverted optical .