Friction and wear in threaded surfaces of rotary drill collars

Journal Article · Mon Mar 01 00:00:00 EST 1993 · Journal of Energy Resources Technology; (United States)

DOI:https://doi.org/10.1115/1.2905966· OSTI ID:6788278

Thornton, H R ^[1]; Bailey, E I ^[2]; Williamson, J S ^[3]

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1. Texas A and M Univ., College Station (United States)
2. Stress Engineering Services, Inc., Houston, TX (United States)
3. Smith International, Inc., Houston, TX (United States)

Two surfaces, under high normal stress, in sliding contact provide the basis for friction and wear studies within rotary drill collars. Flat and ring specimens, considering three different contact areas, were rotated to determine the effect of surface finish, coatings, lubricants and normal stress on friction and wear. The 4145 steel specimens were heat-treated to a yield strength of 124,000 lb/in[sup 2] (855 MPa) and a R[sub c] hardness of 28. The torque required to rotate the ring specimen was measured as a function of the rotation angle. The friction coefficient was calculated. Seizure and galling were common for metal-to-metal contact. Rust and phosphate coatings break down under the high normal stress. Metal-filled lubricants produce static coefficients of friction between 0.03 and 0.25 and dynamic coefficients between 0.04 and 0.26. Seizure and galling were not observed.

• OSTI ID: 6788278
• Journal Information: Journal of Energy Resources Technology; (United States), Vol. 115:1; ISSN 0195-0738
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ROTARY DRILLS
THREADED JOINTS
SLIDING FRICTION
WEAR
COATINGS
HARDNESS
HEAT TREATMENTS
IRON OXIDES
LUBRICANTS
PHOSPHATES
STEELS
STRESSES
YIELD STRENGTH
ALLOYS
CHALCOGENIDES
DRILLING EQUIPMENT
DRILLS
EQUIPMENT
FRICTION
IRON ALLOYS
IRON BASE ALLOYS
IRON COMPOUNDS
JOINTS
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360103* - Metals & Alloys- Mechanical Properties