Investigating the Microstructure and Wear Properties of AISI 4140 Steel Clad with WC-Ti Composite Particles Via Gas Tungsten Arc Welding

AISI 4140 steel, known for its strength and wear resistance, is widely used in the oil industry, particularly for drilling equipment. However, its wear resistance varies based on the environment and drilling conditions, necessitating additional surface modifications for optimal performance. This paper investigates the microstructure and wear performance of AISI 4140 steel clad with WC-Ti composite powder using gas tungsten arc welding. Four different WC-Ti powders were used, with the Ti content ranging from 10 wt% to 40 wt%. The welding parameters were kept constant, except for the current intensity which was varied between 100 A and 120 A. The through-thickness micro-hardness profile and wear resistance were evaluated. Examinations revealed that, by increasing the current intensity from 100 A to 120 A, the size of the dendrites in the weld region grew. Simultaneously, mechanical properties such as hardness and wear resistance diminished. It was also found that, with the increase in the titanium content of the composite powder, the size of the dendrites decreased. The micro-hardness results indicated a rise in surface hardness from 250 HV (base metal) to a maximum of 850 HV (cladding). The higher the content of Ti in the composite powder, the greater the hardness and wear resistance of the cladding.