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Over past decades, outbreaks of endoscopy-associated infections have resulted in illness and even death in a considerable number of patients, with most of the infections attributed to improper reprocessing of endoscopes [1][2]. We excluded endoscopes with special structural features (i. e. small-bowel endoscopes, magnifying endoscopes, echoendoscopes, duodenoscopes, therapeutic endoscopes), and endoscopes requiring repeat reprocessing because of unqualified microbiological surveillance results. Endoscopes were withdrawn if any of the following applied: malfunction or damage was found at any stage of reprocessing; there was a personnel change during cleaning; the automated brushing or the automated endoscope reprocessor cycle was interrupted due to human error or program failures; or sampling was not performed due to incorrect delivery after drying. [Extracted from the article]

The uniaxial ratchetting behavior and cyclic softening/hardening characteristics of Fe‐0.4C‐7Mn‐3.2Al steel are revealed by cyclic loading experiments. Electron backscattered diffraction (EBSD) and X‐ray diffraction (XRD) analyses have been carried out for assessing retained austenite (RA) transformation during cyclic deformation. Fe‐0.4C‐7Mn‐3.2Al steel exhibits a gradual transition from cyclic stabilization to slight cyclic hardening with increasing strain amplitude. RA transformation is one of the reasons for cyclic hardening. The ratchetting of Fe‐0.4C‐7Mn‐3.2Al steel shows two different characteristics under asymmetrical cyclic stressing. When the stress amplitude is below a certain value, the ratchetting is similar to that of typical cyclic stabilized materials in three stages of deceleration, stabilization and acceleration. However, when the stress amplitude reaches a certain level, the ratchetting evolution accelerates from the beginning to the fracture. The results show that the interaction between transformation‐induced plasticity and ratchetting strain can lead to accelerated accumulation of plastic strain. Highlights: The uniaxial ratchetting behavior and cyclic softening/hardening characteristics of a medium manganese steel are revealed.The transformation of retained austenite (RA) during cyclic deformation is analyzed.The interaction between transformation induced plasticity and ratchetting can lead to accelerated accumulation of plastic strain. [ABSTRACT FROM AUTHOR]

The microstructures and mechanical properties of Fe–0.35C–3.2Al–5Mn (in wt%, same later) hot‐rolled medium‐manganese steels are systematically investigated. The results show that ultrafine‐grained duplex phases with bimodal morphologies of lath and equiaxed are obtained with intercritical annealing at 750 °C for 1 h, along with ultimate tensile strength of 950 MPa and total elongation of 71.2%, attributed to the dislocation slip and deformation of ferrite matrix, accompanied by the synergetic twinning of retained austenite plus transformation of retained austenite to martensite. The newly developed medium‐manganese steels, which exhibit an excellent product of ultimate tensile strength and total elongation of 67.6 GPa·%, demonstrate great practical applications. [ABSTRACT FROM AUTHOR]

The effects of annealing conditions on the microstructure and deformation mechanism of 0.17C-9Mn-3.5Al steel have been investigated. Through austenite reverted transformation (ART) annealing, a multiphase microstructure composed of δ-ferrite, α-intercritical ferrite, γ-austenite, and α'-martensite is obtained in as-forged specimens. For the specimen annealed at 750 °C for 60 min, a high volume fraction (42.19%) of retained austenite is attained, yielding a large total elongation (TE) of ≈38% and tensile strength ( Rm) of ≈810 MPa and a two-stages work hardening behavior. The work hardening behavior analysis using the differential C-J model clarifies that the multistage can be mainly attributed to the discontinuous transformation induced plasticity (TRIP) effect, which is related to the volume fraction of retained austenite and its different stability levels as well as cooperative deformation of the multiphase microstructure. Thus, the active TRIP effect predominately affects the high strain stage, resulting in a higher work hardening ability and a increased plasticity. [ABSTRACT FROM AUTHOR]

By altering the temperature and duration of intercritical annealing (IA), the mechanical stability of retained austenites (RAs) is intentionally regulated in newly designed cold‐rolled medium manganese steel of Fe‐0.4C‐7Mn‐3.2Al (in wt%). Consequently, a novel combination of ultimate tensile strength (UTS) and total elongation (TE) (e.g., 1118 MPa and 67%) is obtained in duplex steel, and the corresponding product of UTS and TE can reach 75 GPa%. Both twinning‐induced plasticity (TWIP) and transformation‐induced plasticity (TRIP) take effect step by step during deformation and are conducive to the outstanding properties. [ABSTRACT FROM AUTHOR]