The invention relates to the field of
austenitic stainless steel material
welding, in particular to an SA-213TP347HFG steel small
diameter tube
welding method.The method comprises the following steps: 1, conducting treatment before
welding, wherein a V-shaped groove is machined out of an SA-213TP347HFG steel small
diameter tube to be welded, the single-side groove angle is 33-38 degrees, and
grinding treatment is conducted on the groove; 2, controlling the welding environment, wherein the temperature is higher than or equal to 0 DEG C, the air speed is less than or equal to 2 m / s, and the
relative humidity is less than or equal to 75%; 3, welding the tube to be welded through manual
tungsten inert gas
arc welding (TIG), wherein an TIG welding
machine with
high frequency arc striking and current attenuation is selected, the electric arm length in the
welding process is 1-2.5 mm, an ERNiCr-3 welding wire is selected, the welding root is filled with
argon and coated with an anti-oxidation protective agent for protection, the
argon purity is 99.99%,and the flow rate is 8-15 L / min, narrow
weld bead and short bead intermittent welding is adopted, tracking is conducted from time to time for
temperature measurement so that the welding interlayer temperature cannot be higher than 70 DEG C, weld lines on each layer are covered with cloth dipped in
purified water for cooling, and in the
welding process, a slope with length being 7-9 mm is formed through
grinding at a joint between each
weld line and the previous
weld line.