Untersuchung einer mehrlagigen Schweißnaht eines dickwandigen Rohres aus dem austenitischen Stahl X6 CrNiNb 18 10

In this paper, microstructure and residual stresses of a multi pass welding of a thick walled tube made of austenitic stainless steel X6 CrNiNb 18 10 1.4550 are systematically characterized and assessed. Results of microstructural and phase analyses, residual stress and hardness measurements as well as of a tensile test using micro specimen and SEM analyses are presented. Using these data, plastic deformations occurring during the welding process in the vicinity of the weld seam are evaluated. Finally, consequences of an additional heat treatment at 400 C 24 h are studie

Prevention

Rare but regularly recurring complications are leading to ongoing regulation of the commercial, non-medical whole-body electromyostimulation (WB-EMS) market. In addition to the revised German Radiation Protection Statutes (NiSV), the Deutsche Industrie Norm (DIN) 33961-5 was recently published with safety policies for WB-EMS application, anchoring both relative and absolute contraindications for WB-EMS for the first time. The purpose of this article is to justify the rationale of contraindications in a commercial setting and to support their consistent application.While the relative contraindicationsappear plausible and uncritical, absolute contraindications for WB-EMS are much more debatable. In fact, some absolute contraindications (e.g. diabetes mellitus) could be safely addressed by WB-EMS at least after careful medical anamnesis and competent, close supervision. However, this requires sound knowledge of WB-EMS on the part of physicians and instructors, low user-trainer ratios and prompt medical care in an emergency.However, considering the multitude of different settings of commercial WB-EMS, in extreme cases with hardly supervised, only video-guided WB-EMS sessions, the necessary accurateness and expertise for safe WB-EMS is not always guaranteed. That there is no mandatory licensing of WB-EMS instructors, the key players in WB-EMS, underscores the concern. Whilst acknowledging the multitude of high-quality suppliers, it is advised thatthe commercial, non-medical WB-EMS sector as a whole to be wary of indications with significantly increased complication potential. Lastly, the mandatory acceptance of the contraindications listed in DIN 33961-5 might be considered as an inevitable step towards preventing overregulation by official authorities.KEY WORDS: Whole-Body Electromyostimulation, DIN 33961-5, Commercial Application, Guidelin