In conducting the welding process, the welder is advised to pay attention to the variables that affect the quality of the weld. For example, the state of the electrode. Welding electrodes are very sensitive to air conditions in the welding chamber. Electrodes used in the SMAW welding process need to be stored in a special place that meets the following conditions: dry, no oil, protected from dust. SMAW electrodes must be placed with care. Damage to the electrode causes the compounds contained in the flux to easily react with gases in the air. A welder must pay attention to doing the SMAW welding process properly and correctly. Welder need to understand and apply applicable procedures.
WPS is a written and qualified procedure used to provide guidance to the implementer (welder/welding operator). WPS contains important, additional important and unimportant variables according to the welding process used. in the WPS document, variable data refers to PQR. Changes can be made to non-essential variables to match production demands without requiring re-qualification. PQR is a record of all the data used for testing the test coupon. PQR records all variables used during test welding and testing including the results.
Welding Procedure Variable
Welding techniques are sought after by some people who want to learn to weld. We can get these techniques in vocational or technical schools. and plus welding related courses.
In the welding procedure, the variables of all the elements involved, must be properly identified and controlled. Because welding is a special process (special process), if the welding procedure variables have been made well, we expect the welder’s results to be better. To find out the results of the weld after the welding is complete, the welding inspector (quality control) conducts an inspection with tools such as visual tests, PT, MT, UT, RT, eddy current and other tools.
VARIABLES in WPS
Welding variables are divided into 3 groups, namely:
1. essential variables, namely variables which, if changed, will need to be retested, namely those that affect mechanical properties. welding process, filler metal,, electrode, preheat.
2. Non-essential variables are variables that have no effect on mechanical properties and do not need to be retested in case of replacement, including connection design, cleaning etc.
3. Supplementary essential variables are variables that affect the toughness (toughness) of the weld, such as changes in the welding process, vertical welding up and down, and post welding.
after all meet the procedures, it is necessary to test specimens (coupon test) to obtain the required test specimens.