Materials and Corrosion-werkstoffe Und Korrosion最新文献

Corrosion of condenser circuits in refrigeration systems significantly impacts appliance reliability and longevity. This study investigates an unreported cause linked to changing adhesive materials during copper pipe assembly. Transitioning from a polyethylene-based adhesive to one containing ethylene vinyl acetate caused unexpected perforation of copper coils within months. We hypothesized that even trace amounts of acetic acid, a byproduct of the latter adhesive, trigger a peculiar localized morphology known as “ant-nest corrosion.” We propose using ethylene vinyl acetate-free adhesives to prevent this issue in refrigeration systems.

Cover:

Optical microscopy images of as tested C-276 C-rings. Pitting corrosion was evident on the stressed inner edge of the C-rings and on the surface. A more detailed analysis showed that also intercrystalline corrosion had taken place with the loss of occasional grains because of the applied stress in combination with corrosion.

More detailed information can be found in: Daniel Blücher, Torstein Lange, Judit Sandquist, Inge Saanum, Mikko Uusitalo, Corrosion performance of different alloys exposed to HTL conditions—a screening study, Materials and Corrosion 2024, 75, 1258.

A system for analysing steel plates is presented for an application in the wind power industry. The objective of the system is to assess the surface roughness as a preliminary step for the application of an anti-corrosion coating. A number of noncontact sensor systems were considered, with the laser triangulation scanner proving to be the optimal solution. The samples are analysed in a test stand and the roughness is measured with this optical system. At the same time, the surface is recorded with a CMOS camera. An AI model is created from the sensor fusion of both systems, which can classify individual segments of the surface as well or poorly blasted. In the following step, the surface roughness is estimated as the R_z parameter by another AI model. An error of less than 6 μm is achieved.

This study investigates the influence of cathodic polarization on the chloride threshold (C_T) for carbon steel in alkaline solutions, analogous to reinforcing steel embedded in concrete, with a focus on the electrochemical steel potential as a critical factor for corrosion initiation. The research, incorporating a literature review and potentiostatic tests, reveals that C_T shows potential independence at potentials more anodic than −200 mV_SCE and increases for potentials more cathodic than −200 mV_SCE. The observed increase in C_T under cathodic polarization is attributed to alterations in the passive layer composition, supporting the existence of distinct potential regions that govern the onset of corrosion.

As an important infrastructure for oil and gas transportation, the safe and stable operation of long-distance pipelines is significant for guaranteeing national energy security and economic development. However, pipelines are susceptible to corrosion due to various factors. Therefore, it is crucial to take effective corrosion protection measures. Pulse current cathodic protection technology, as an advanced pipeline corrosion protection technology, is superior to traditional cathodic protection technology. This paper mainly summarizes the research progress of pulse current cathodic protection technology for long-distance pipelines in recent years. It briefly discusses the protection mechanism, characteristic parameters, challenges, and development trends of pulse current cathodic protection technology, which provides a useful reference for the further promotion and application of pulse current cathodic protection technology for long-distance transport pipelines.