To improve mechanical properties and increasing useful life of metal pieces, different methods of welding are used for repairing surface
crack of metal pieces. In this research, performance of flame welding method by spraying pure iron powder evaluated for repairing surface
grooves of structural steel. First, four specimens including one control specimen and other three specimens grooved specimens in depth of
1mm and in length of 12.5mm and groove width in the sizes of 0.5, 0.75 and 1mm.were prepared then, powder melted using oxyacetylene
reducing flame and spraying iron powder in the flame path and attached to the inner surface of the groove and finally, the specimen
repaired. Results showed that after repairing surface groove, tensile strength of the repaired specimens were reached to the tensile strength
of control specimen with the margin of 2.5%.