Laminar corrosion defects, such as intergranular penetrations and stress corrosion cracks, are common in ageing aircraft. These defects are most commonly found in extruded and rolled sections made from high strength aluminium alloys; typical examples include wing and tailplane spar caps in widespread use in ageing aircraft. They present a significant problem in that the assessment of their sign...

A progress report of the ret arch invest carried out on the problem of stress-cor high strength materials under ARPA Order Work at Carnegie-Mellon University, Lehi Georgia Institute of Technology, The Boe American University, and the Naval Resea cerning test techniques, materials chara metallurgy, surface studies, and corrosi described. The report is divided into t covering work on high strengt...

The potentiodynamic polarization test and slow strain rate tensile tests of X80 pipeline steel were performed in 0.5M Na2CO3-1M NaHCO3 solution to study the electrochemical and stress corrosion cracking properties. The results of potentiodynamic polarization test show that there is an obvious stable passive region, about from 0v to 0.8V (SCE), indicating that anodic protection is feasible. The ...

AE monitoring from various types of stress corrosion cracking (SCC) has been conducted for the past 15 years in our laboratory. This paper discusses AE results of active-path dissolution-type SCC of austenitic stainless steel in chloride solution and fused salt, fluoride and polythionic acid solutions, brass in ammonia (Mattosson's solution), and carbon steels in nitrite solution. Transgranular...

The paper presents a new analytical model to study the evolution of radial cracking around a corroding steel reinforcement bar embedded in concrete. The concrete cover for the corroding rebar is modelled as a thick-walled cylinder subject to axisymmetrical displacement constraint at the internal boundary generated by expansive corrosion products. A bilinear softening curve reflecting realistic ...

The filling of strand corrosion products during concrete crack propagation is investigated experimentally in the present paper. The effects of stirrups on the filling of corrosion products and concrete cracking are clarified. A prediction model of crack width is developed incorporating the filling proportion of corrosion products and the twisting shape of the strand. Experimental data on cracki...

Cost functions, associated with the gamma process for modelling deterioration, are extended to include multiple failure modes. The application of these cost functions is demonstrated by an example in the process industry. We consider an elbow in a pipeline, which is susceptible to thinning due to corrosion and stress corrosion cracking. The optimal inspection interval and replacement levels are...

In this work, Slow Strain Rate Test (SSRT) testing, Light Optical Microscopy (LOM) and Scanning Electron Microscopy (SEM) were used to study the effect of microstructure, corrosive environments and cathodic polarisation on stress corrosion cracking (SCC) of two grades of high strength steels, Type A and Type B. Type A is manufactured by quench and tempered (Q&T) method. Type B, a normalize stee...