Search
Filters
Close

09077 Development of Spring and Fastener Characteristics for Alloy 725 for Oil and Gas Applications

Product Number: 51300-09077-SG
ISBN: 09077 2009 CP
Author: Jan Edwards, Seth A. Silverman and Rashmi B. Bhavsar
Publication Date: 2009
$0.00
$20.00
$20.00
Alloy 725 is a precipitation hardenable nickel-chrome-molybdenum alloy with higher molybdenum content than generally used in common nickel-based alloys used in oil gas applications. This alloy is used where high strength and superior corrosion resistance is required. It is listed in NACE MR0175/ISO15156 at a maximum hardness of 43 HRC in the annealed and aged condition. There are applications where higher strength along with corrosion and cracking resistance are required such as springs, fasteners and pump shafts. Alloy X-750, MP35N and Elgiloy are common spring materials for oil and gas application containing sour fluids. With the high cost of raw materials MP35N is very expensive for many applications whereas X-750 may be marginal or not accepted by oil companies in sour environments. Alloy K-500 is used in some bolting applications but hydrogen charging can be a concern in certain environments. The ability for alloy 725 to be cold worked and aged to higher strength levels offers opportunities to use the alloy at the relatively high strength levels required for springs, pump shafts and fasteners. This paper presents the work done to optimize the heat treatment of 45% cold reduced 725 to achieve the desired mechanical properties for these applications. Stress corrosion testing for this alloy was carried out in the spring temper (cold worked and aged condition). The results of initial studies are presented in this paper.

Keywords: 725, nickel-based, springs, completion equipment, pump shafts, fasteners, and service tools
Alloy 725 is a precipitation hardenable nickel-chrome-molybdenum alloy with higher molybdenum content than generally used in common nickel-based alloys used in oil gas applications. This alloy is used where high strength and superior corrosion resistance is required. It is listed in NACE MR0175/ISO15156 at a maximum hardness of 43 HRC in the annealed and aged condition. There are applications where higher strength along with corrosion and cracking resistance are required such as springs, fasteners and pump shafts. Alloy X-750, MP35N and Elgiloy are common spring materials for oil and gas application containing sour fluids. With the high cost of raw materials MP35N is very expensive for many applications whereas X-750 may be marginal or not accepted by oil companies in sour environments. Alloy K-500 is used in some bolting applications but hydrogen charging can be a concern in certain environments. The ability for alloy 725 to be cold worked and aged to higher strength levels offers opportunities to use the alloy at the relatively high strength levels required for springs, pump shafts and fasteners. This paper presents the work done to optimize the heat treatment of 45% cold reduced 725 to achieve the desired mechanical properties for these applications. Stress corrosion testing for this alloy was carried out in the spring temper (cold worked and aged condition). The results of initial studies are presented in this paper.

Keywords: 725, nickel-based, springs, completion equipment, pump shafts, fasteners, and service tools
Product tags
Also Purchased
Picture for UNS N07725 NICKEL ALLOY CONNECTION FAILURE
Available for download

51312-01095-UNS N07725 NICKEL ALLOY CONNECTION FAILURE

Product Number: 51312-01095-SG
ISBN: 01095 2012 CP
Author: Steve S. Shademan
Publication Date: 2012
$20.00
Picture for Embrittlement of MP35N (UNS R30035) Springs in Simulated Downhole Production and Acid Treatment Envi
Available for download

51312-01156-Embrittlement of MP35N (UNS R30035) Springs in Simulated Downhole Production and Acid Treatment Envi

Product Number: 51312-01156-SG
ISBN: 01156 2012 CP
Author: Karthik Krishnan
Publication Date: 2012
$20.00