- By zuuk
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To develop a custom weld procedure, one must:
- Determine the needed result (from using this procedure). Conceptually engineer a solution to encompass Material, Material form, Material thickness and Weldability
- Establish the welding parameters including volts/amps, travel speed for depositing metal, heat input, electrical characteristics (pulse or non-pulse), and secondary requirements (pre and post weld heat treatment).
- Design the procedure based on all the above
- Perform the weld and record every variable during the process:
- Prior to welding: Geometry of joint design, Test piece position and Pre-heat temperature
- During welding: Volts, Amps and Welding current polarity, Current characteristics, Travel speed, Heat input, Weld thickness and number of passes
- Post welding: Non-destructive testing, Post weld heat treat (if required) and Destructive testing
Results from the destructive testing are evaluated using the test piece’s mechanical properties. More specifically, the tensile strength, yield strength and elongation percentage, hardness values and impact tests (if required).
The procedure is acceptable if the test piece meets or exceeds requirements for these mechanical properties as defined by the AWS or ASME Code as applicable.
 Prior to welding, heat is applied to meet or improve the metallurgical properties of certain metals. This also could be for the removal of hydrogen from those metals susceptible to hydrogen embrittlement. All metal properties are impacted by time and applied heat.