This paper analyzes pitting corrosion at the weld zone and at the heat affected zone (HAZ) in AISI 304 rolled stainless steel welds. As the aforementioned material is one of the most frequently used types of stainless steel, it is needful to be aware of the mechanisms that lead to its deterioration, like corrosion, since it can cause failures or malfunction in a wide variety of products and facilities. For the experimental tests 1.5 mm thick AISI 304 stainless steel plates were welded and rolled to different thicknesses and after, the samples were subjected to mechanical and corrosion tests and to a micrograph study. Deformation stresses and other intrinsic metallurgic and physic-chemical transformations that occur during cold rolling and welding, and that are key factors in the anti-corrosion behavior of AISI 304 rolled stainless steel, have been observed and analyzed. A correlation has been found between cold work levels in test samples and number of pits after corrosion tests.

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Although both wear and fatigue are inevitably associated with the wheel/rail contact, they are normally studied as different phenomena and both are commonly considered excluding. Wear of railway wheels and rails is usually studied by relating wear rate to the T γ or T γ/A parameters or by plotting the so called "wear maps", where different rolling parameters are related to the wear rate. On the other hand, fatigue in wheel/rail contact is mainly studied from the surface and subsurface stress or deformation fields and from the crack growth rate.However, one of the main causes of wear in rolling contact is the loss of material due to delamination processes that have their origin in the presence of surface fatigue cracks. So, if wear and fatigue are related, it should be possible to study both of them using the same method.In this paper, the fatigue index, based on the shakedown theory and used to predict the surface initiated fatigue of railway wheels, is proposed as a means to study the wear rate in rolling contact. The fatigue index is directly related to the apparition and growth of fatigue cracks at the surface and, thus, directly related to the peeling and spalling processes that constitute the severe and catastrophic wear mechanisms.The data collected from a series of twin-disc tests show that the wear rate correlates with the fatigue index following an exponential evolution independently of the normal load. Furthermore, a fatigue index around 0 marks the onset of severe wear.

The design of the formative and summative assessment processes is of paramount importance to help students avoid procrastination and guide them towards the achievement of the learning objectives that are described in the course syllabus. If the assessment processes are poorly designed the outcome can be disappointing, including high grades but poor learning. In this paper, we describe the unexpected and undesirable effects that an on-demand formative assessment and the timetable of a summative assessment that left the most cognitively demanding part, problem-solving, to the end of the course, had on the behavior of students and on both grading and learning. As the formative assessment was voluntary, students procrastinated till the last minute. However, the real problem was that due to the design of the summative assessment, they focused their efforts mainly on the easiest parts of the summative assessment, passing the course with ease, but achieving a low learning level, as evidenced by the low scores of the problem-solving part of the summative assessment.