The chloride stress corrosion cracking behavior of beryllium copper and other nonmagnetic drill collar alloys

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7005640

Turn, Jr, J C

Nonmagnetic drill collars and other structural components are used to provide a region in the bottom hole assembly near the bit in which sensitive magnetic measurements can be made. Beryllium copper, Cl7200, is paramagnetic with low magnetic permeability which makes it aptly suited for nonmagnetic components. Not only are the magnetic properties of the alloys for these components important, but the integrity of the alloys under dynamic loading in a range of hostile drilling fluids is critical as well. Chlorides in certain drilling muds can cause unpredictable stress corrosion cracking (SCC) of susceptible alloys. In a standard test for chloride SCC, ASTM G 36-73, beryllium copper, Cl7200, showed no failure after 1000 hr of exposure to boiling 45 weight percent magnesium chloride solution. The applied stresses were 100 percent of the 0.2 percent offset yield strength for the alloy. Failures for austenitic stainless steels generally occurred in less than 200 hr in this environment at applied stresses of 25 percent of the yield strength. Although benefits can be obtained by controlling the environment and introducing residual compressive stresses to austenitic stainless steel components, these remedies cannot permanently eliminate the underlying susceptibility of these alloys to chloride SCC. Beryllium copper is immune to chloride SCC.

• OSTI ID: 7005640
• Report Number(s): CONF-870314-
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALINE EARTH METAL COMPOUNDS
ALLOY SYSTEMS
ALLOYS
AUSTENITIC STEELS
BERYLLIUM ALLOYS
BINARY ALLOY SYSTEMS
BOILING
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
COMPRESSION STRENGTH
COPPER ALLOYS
CORROSION
CORROSION RESISTANCE
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
CRACK PROPAGATION
DESTRUCTIVE TESTING
DRILLING EQUIPMENT
DRILLING FLUIDS
DRILLS
EQUIPMENT
FLUIDS
FRACTURE MECHANICS
HALIDES
HALOGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
MAGNESIUM CHLORIDES
MAGNESIUM COMPOUNDS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICS
PHASE TRANSFORMATIONS
SLEEVES
STAINLESS STEELS
STEELS
STRESS CORROSION
TESTING
YIELD STRENGTH