High-Strength Steel Component Inspection for Sustained Stresses Using Magnetic Property Sensing Navy SBIR FY2010.2 Sol No.: Navy SBIR FY2010.2 Topic No.: N102-136 Topic Title: High-Strength Steel Component Inspection for Sustained Stresses Using Magnetic Property Sensing Proposal No.: N102-136-0816 Firm: JENTEK Sensors, Inc. 110-1 Clematis Avenue Waltham, Massachusetts 02453-7013 Contact: David Grundy Phone: (781) 642-9666 Abstract: A method for nondestructive measurement, characterization, and mapping of sustained stresses in high-strength steel components, using magnetic stress gages (MSG), is proposed. The goal is to provide a nondestructive inspection (NDI) tool for locating specific areas within the components, where high tensile sustained stresses exist making them susceptible to environmentally assisted cracking. This NDI tool will take advantage of the unique capabilities of model-based stress gages such as scanning MWM-Array sensors. In Phase I, JENTEK will perform measurements with the MSG sensors on two types of coupons (in the Base Effort) and on component samples (in the Option Effort) to determine feasibility of measuring the state and magnitude of sustained stresses in primary aircraft structure steel components. JENTEK will perform measurements in two modes: stationary and scanning, in two orientations. In the stationary mode, we will measure on a coupon to demonstrate sensitivity to various levels of sustained stresses and to determine the correlation between the magnetic permeability and stresses for the selected material. In the scanning mode, we will generate maps revealing the residual stress distribution. This latter mode is to be used ultimately on actual rotorcraft components, particularly at the locations where high tensile sustained stresses are likely. Benefits: The successful completion of the proposed Phase I program will result in the capability to nondestructively identify locations on high-strength steel components that are susceptible to environmentally assisted cracking. This would be particularly applicable to high-strength steel structures exposed to seawater, and essential for sustained readiness of Navy aircraft. In Phase II, this capability will be taken to the level that is consistent with practical implementation of an economically and functionally viable stress measurement system, potentially enabling the development of NDI systems for ships, offshore platforms, seaside process, petrochemical and power plants, and tension cables used in bridges. Return