Investigation of the structure and mechanical properties of welded joints in steels of the K56 strength grade in different welding conditions

Abstract

The results of investigations of the effect of the welding conditions of manual arc welding on the structure and mechanical properties of the welded joints in low-carbon, low-alloyed pipe steels of the K56 strength grade are presented. It is shown that in welding in different combinations of welding current and welding speed, the superheated zone of the heat-affected zone (HAZ) is characterized by the formation of ferrite and pearlite in the form of grains and Widmanstätten structure. The experiment planning method is used to determine the regression dependences of the hardness and impact toughness of the metal of the superheated zone on the controllable welding parameters.

Keywords::

• pipe steel
• welding current
• welding rate
• hardness
• impact strength