Innovations in Heater Technologies for Optimized Heating during Welding

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Sustainment OBJECTIVE: Develop and demonstrate reliable preheat and post weld heat treatment technology that can consistently heat and operate at temperatures up to 1000 F in a shipyard environment and in accordance with Navy requirements. DESCRIPTION: Preheating and post-weld heat treatment are common requirements for the fabrication of Naval platforms. Preheating is required on a variety of naval alloys including high yield (HY) steels, high strength low alloy (HSLA), mild steel, stainless steel, copper nickel, nickel copper, and aluminum. Depending on material and thickness, temperatures can vary up to 1000 F. In the past, heater bars could be repaired but recently the devices have changed from repairable tools to a consumable product. When heater bars, power streamer cords, or control units are broken, there is no alternative process to preheat the materials. Critical units are forced to stop and wait for equipment to become free to continue the process, leading to delays throughout the entire shipbuilding process. Heater bars and power streamer cords are no longer durable or reliable, and the current products have a lifecycle that is unpredictable. Some common issues with the heater bars are electrical shorts, connector burn out, and critical failure of the heating element. If any part of the heater bar breaks, the entire unit is unusable. Other limits such as their shapes, weights, and lack of technology monitoring impede use for specific applications requiring unique methods to ensure the products are properly heated prior to or during the welding process, which increase costs. Currently no alternative preheating solutions are suited for shipbuilding environments and there is a lack of availability and innovation in the industry to meet this requirement. The current technology is antiquated with little to no advancement in recent years. Current heating methods (induction and resistance) have availability, attachment, control, and monitoring issues that negatively impact process methods and costs. The goal of this SBIR topic is to develop and pilot an improved technology for pre- and post-steel heating for welding. The project will investigate and identify the technology needs such as temperature control and increased durability. In addition to currently using inductive and resistive heating, other technologies could be explored. PHASE I: Explore existing and innovative heating technologies and control mechanisms to identify a solution that can meet the Navy requirements found in reference documents such as Tech Pub 278 and Tech Pub 1688 [Refs 1,2]. Demonstrate the feasibility by a breadbox demonstration. In addition to developing the heater the proposal should address reparability, and sustainability, and data monitoring capability of the heater and control unit. Prepare a Phase II plan. PHASE II: Develop an appropriate hardware to insert the technology in a shipyard environment. Demonstrate the robustness of the technology, reparability of the heating system, and data monitoring and control capabilities of the system. PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the system and control unit, if successful, to all OEMs for naval platforms including private shipyards, public shipyards, and various repair and sustainment facilities. This technology would be applicable to all naval facilities that perform welding operations in both acquisition and sustainment. REFERENCES: 1. NAVSEA-S9074-AR-GIB Requirements for Fabrication Welding & Inspection, & Casting Inspection & Repair for M. https://www.document-center.com/standards/show/NAVSEA-S9074-AR-GIB 2. T9074-AD-GIB-010/1688: NAVSEA Technical Publication Requirements for Fabrication, Welding, and Inspection of Submarine Structure Rev. 1. http://everyspec.com/USN/NAVSEA/T9074-AD-GIB-010_1688_REV-1_51915/ KEYWORDS: Preheat; post-weld heat treatment; welding; temperature control; temperature monitoring; data capture; heaters