OCTOBER 12, 2018 — Naval Sea Systems Command (NAVSEA) has approved the first metal part created by additive manufacturing (AM) for shipboard installation.
Produced by Huntington Ingalls Industries' (NYSE: HII) Newport News Shipbuilding division, this first certified 3D-printed metal part—a prototype piping assembly called a pipe drain strainer orifice (DSO)— will be installed on the aircraft carrier USS Harry S. Truman (CVN 75) early next year. After its installation, the assembly will be tested onboard the ship for one year. The DSO assembly is a steam system component that permits drainage/removal of water from a steam line while in use.
"This install marks a significant advancement in the Navy's ability to make parts on demand and combine NAVSEA's strategic goal of on-time delivery of ships and submarines while maintaining a culture of affordability," said Rear Adm. Lorin Selby, NAVSEA Chief Engineer and Deputy Commander for Ship Design, Integration, and Naval Engineering. "By targeting CVN 75 [USS Harry S. Truman], this allows us to get test results faster, so — if successful — we can identify additional uses of additive manufacturing for the fleet."
Test articles passed functional and environmental testing, which included material, welding, shock, vibration, hydrostatic, and operational steam, and will continue to be evaluated while installed within a low temperature and low pressure saturated steam system. After the test and evaluation period, the prototype assembly will be removed for analysis and inspection.
While the Navy has been using additive manufacturing technology for several years, the use of it for metal parts for naval systems is a newer concept and this prototype assembly design, production, and first article testing used traditional mechanical testing to identify requirements and acceptance criteria. Final requirements are still under review.
"Specifications will establish a path for NAVSEA and industry to follow when designing, manufacturing and installing AM components shipboard and will streamline the approval process," said Dr. Justin Rettaliata, Technical Warrant Holder for Additive Manufacturing. "NAVSEA has several efforts underway to develop specifications and standards for more commonly used additive manufacturing processes."
"This is a watershed moment in our digital transformation, as well as a significant step forward in naval and marine engineering," said Charles Southall, Newport News' vice president of engineering and design. "We are committed to partnering with the Navy to ensure that collectively, we are investing in every opportunity to improve and advance the way we design and build great ships for the Navy."
The additive manufacturing process recently approved by NAVSEA is a highly digitized process that deposits metal powder, layer by layer, to create three-dimensional marine alloy parts that potentially replace castings or other fabricated parts, such as valves, housings and brackets.
Huntington Ingalls says that adoption of 3-D printing of metal parts is the culmination of years of work with Navy and industry partners that involved the rigorous printing of test parts and materials, extensive development of an engineered test program and publishing of the results, and could lead to cost savings and reduced production schedules for naval ships.
Earlier this year, Newport News announced a joint development agreement with 3D Systems that resulted in the installation of the ProX DMP 320 high-performance metal additive manufacturing system at the facility.
"We have delved into uncharted territory to create a positive disruption in our industry in much the same way the modern welding processes supplanted rivets, revolutionizing the way ships are built," Southall said. "We're proud to be leading the way."