ASTM Welding Procedures A645 to A930

Many manufactures of parts and equipment containing ASTM steels do not use the recommended pre or post-heat treatments.

The requirements for weld heat treatment is greatly influenced by many factors, the application, the governing specifications or codes, the plate condition, plate thickness, the weld consumables the weld procedures, the weld size and amount of welds required.

In many cases the manufacturer that uses ASTM steels will find that its not necessary for the weld to match the mechanical properties of the steel, and will therefore typically utilize low hydrogen, highly ductile E7018 /E70S-3-6 / E71T-1 electrodes.

When using the low hydrogen electrodes, the pre and post heat treatment recommendations are frequently eliminated, however from a weld quality perspective always ensure that the weld locations are dry, the metal is over 60F, and that rust and mill scale is removed from the weld area. Also even when heat treatment is not used its frequently beneficial to not allow the multi-pass inter-pass weld temperatures to exceed 200F

If you ignore the heat treat requirements as recommended by the metal specifications ensure you use low hydrogen electrodes then,

(a) Establish the welding procedure. (b) Qualify the weld and HAZ properties. Ensure the after weld and HAZ properties are compatible with the steel specifications, ref grain size, hardness and strength.