Toughness-optimized weld joints and methods for producing said weld joints
AssigneeExxonMobil Upstream Research Company
InventorsJeffrey R. O'Donnell, Ronald R. Bowen
Life of this patent
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Abstract
Methods for producing toughness-optimized weld joints are provided. A welding procedure that will provide adequate toughness for the center-weld of the weld-joint is developed and used, and a welding procedure that will provide adequate toughness for the surface-weld of the weld-joint is developed and used.
Claims2
A method of welding two pieces of metal to produce a weld joint comprised of a center-weld and a surface-weld, and having a specified thickness and optimized fracture toughness for an intended application, said method comprising the steps of:
- (a) selecting a first non-destructive examination technique that is suitable for detecting surface-breaking discontinuities in a metal used in said intended application;
- (b) determining a minimum surface-breaking discontinuity through-thickness dimension that is readily detectable by said first non-destructive examination technique;
- (c) selecting a second non-destructive examination technique that is suitable for detecting embedded discontinuities in a metal used in said intended application;
- (d) determining a minimum embedded discontinuity through-thickness dimension that is readily detectable by said second non-destructive examination technique;
- (e) determining a first toughness value that is adequate to substantially prevent fracture initiation in said weld joint from surface-breaking discontinuities having a through-thickness dimension that is substantially equal to said minimum surface-breaking discontinuity through-thickness dimension and a second toughness value that is adequate to substantially prevent fracture initiation in said weld joint from embedded discontinuities having a through-thickness dimension that is substantially equal to said minimum embedded discontinuity through thickness dimension;
- (f) designing a surface-weld welding procedure that will produce a surface-weld having a toughness value substantially equal to or greater than said first toughness value and a center-weld welding procedure that will produce a center-weld having a toughness value substantially equal to or greater than said second toughness value;
- (g) creating said center-weld using said center-weld welding procedure;
- and
- (h) creating said surface-weld using said surface-weld welding procedure.
A weld joint having optimized fracture toughness for an intended application, said weld joint having been produced by a method of welding two pieces of metal to produce said weld joint, wherein said weld joint is comprised of a center-weld and a surface-weld and has a specified thickness, and said method comprises the steps of:
- (a) selecting a first non-destructive examination technique that is suitable for detecting surface-breaking discontinuities in a metal used in said intended application;
- (b) determining a minimum surface-breaking discontinuity through-thickness dimension that is readily detectable by said first non-destructive examination technique;
- (c) selecting a second non-destructive examination technique that is suitable for detecting embedded discontinuities in a metal used in said intended application;
- (d) determining a minimum embedded discontinuity through-thickness dimension that is readily detectable by said second non-destructive examination technique;
- (e) determining a first toughness value that is adequate to substantially prevent fracture initiation in said weld joint from surface-breaking discontinuities having a through-thickness dimension that is substantially equal to said minimum surface-breaking discontinuity through-thickness dimension and a second toughness value that is adequate to substantially prevent fracture initiation in said weld joint from embedded discontinuities having a through-thickness dimension that is substantially equal to said minimum embedded discontinuity through thickness dimension;
- (f) designing a surface-weld welding procedure that will produce a surface-weld having a toughness value substantially equal to or greater than said first toughness value and a center-weld welding procedure that will produce a center-weld having a toughness value substantially equal to or greater than said second toughness value;
- (g) creating said center-weld using said center-weld welding procedure;
- and
- (h) creating said surface-weld using said surface-weld welding procedure.
Dependencies are inferred from the claim text.