User talk:Materials Engineer1

You need to click the "resubmit" button at the bottom of the last decline message in order to resubmit the draft; it should not be posted to the AFC Help Desk, but you may ask questions there. 331dot (talk) 20:19, 9 March 2026 (UTC)

Cavitation wear of T91 ferritic–martensitic steel is the degradation of the surface of the heat-resistant ferritic–martensitic steel T91 caused by repeated impacts generated during the collapse of cavitation bubbles in a liquid medium. Cavitation erosion is a significant degradation mechanism in hydraulic and energy systems where metallic components are exposed to flowing liquids, pressure fluctuations, and hydrodynamic loading.^[1]

The phenomenon is relevant for materials used in power engineering equipment, including turbines, pumps, heat-exchange devices, and reactor cooling systems, where cavitation may lead to surface fatigue, crack formation, and progressive material loss.^[2]

== Cavitation erosion ==

Cavitation is a hydrodynamic phenomenon in which vapor bubbles form in a liquid when the local pressure falls below the vapor pressure. When the pressure subsequently increases, these bubbles collapse violently. The collapse generates micro-jets and shock waves capable of producing localized stresses on nearby solid surfaces.^[3]

Repeated bubble collapse near a solid boundary may cause surface plastic deformation, nucleation of microcracks, and progressive removal of material particles. This process is generally referred to as cavitation erosion or cavitation wear.^[4]

Cavitation damage is commonly observed in hydraulic turbines, marine propellers, pumps, valves, and heat-exchange systems, where the interaction between fluid flow and structural materials leads to cyclic mechanical loading of surfaces.

== T91 ferritic–martensitic steel ==

T91 steel is a heat-resistant ferritic–martensitic steel containing approximately 9 wt.% chromium and 1 wt.% molybdenum. It was developed for high-temperature applications in thermal and nuclear power engineering due to its improved creep strength, oxidation resistance, and microstructural stability.^[5]

The microstructure of T91 steel typically consists of tempered martensite laths arranged within prior austenite grains. Strengthening is provided by carbide precipitates such as M₂₃C₆ and fine MX carbonitrides that contribute to thermal stability and creep resistance.^[6]

Because of these properties, T91 steel is widely used in high-temperature pipelines, boilers, steam generators, and other structural components in fossil-fuel and nuclear power plants.

== Cavitation wear behavior ==

The resistance of ferritic–martensitic steels to cavitation erosion depends on several factors including hardness, grain structure, carbide distribution, and the stability of the tempered martensitic microstructure. During cavitation exposure, the material surface undergoes cyclic impacts produced by collapsing bubbles, which may lead to surface fatigue and progressive damage.

Typical stages of cavitation erosion in steels include:

• an incubation period characterized by surface hardening and plastic deformation;
• initiation of microcracks and localized surface damage;
• accelerated material removal;
• stabilization of the erosion rate after prolonged exposure.

These processes are associated with strain accumulation in the surface layer and the formation of pits and microcraters caused by hydrodynamic impacts.

== Experimental studies ==

Experimental investigations of the cavitation wear behavior of T91 ferritic–martensitic steel have been reported in several studies. Rostova, Tolstolutska, Vasilenko and co-authors examined cavitation erosion of T91 steel using ultrasonic vibration testing in accordance with the ASTM G32 cavitation erosion method.^[7]

The authors investigated the microstructure, hardness evolution, and erosion kinetics during cavitation exposure. Their results indicated that the tempered martensitic microstructure of T91 provides relatively good resistance to cavitation-induced degradation compared with some conventional structural steels used in energy systems.

== Applications ==

Due to its high-temperature strength, corrosion resistance, and structural stability, T91 steel is used in a variety of engineering systems where resistance to fluid-induced degradation is important. Typical applications include:

• high-temperature pipelines in power plants
• steam generators and boilers
• heat exchangers
• hydraulic machinery components
• nuclear reactor cooling systems

Improving the resistance of such steels to cavitation erosion is important for extending the service life and reliability of energy equipment.

== See also ==

• Cavitation
• Cavitation erosion
• Ferritic–martensitic steel
• Tribology

== References ==

Materials Engineer1 (talk) 20:23, 9 March 2026 (UTC)

Please use better edit descriptions when you add material. The edit descriptions for the sources and information that you added to Tribology were much too brief. As a consequence @Smokefoot thought that they were probably WP:Refspam, which we do not allow. Since I have published fairly extensively in tribology I know those sources and the authors, so I restored your changes. I do not blame Smokefoot, the edits did look dubious, and unless one is knowledgeable in the field their relevance would not be clear.

N.B., it is better to add more than just one or two sentences. Ldm1954 (talk) 20:27, 10 March 2026 (UTC)

Continuing, I had a minor emergency to deal with. Taking as one example your first edit on wear, something like:

The tribological behavior of structural alloys during sliding friction is strongly influenced by microstructure and phase composition. For instance, austenitic manganese steels and manganese cast irons exhibit complex wear mechanisms associated with strain hardening, plastic deformation of the surface layer and the formation of wear products during sliding.[ref] The addition of XYZ can increase the hardness, thereby reducing wear rates by ABC[ref] while complex mixing as reported by Rigby [ref] can ....

I am sketching out a more encyclopedic and informative section, rather than the two sentences that you added which did look a bit like you were adding refs to your own work if one did not know more -- and adding refs to your own work is not appropriate. Our aim is to provide useful information for non-experts at a somewhat technical level, but not too technical. Ldm1954 (talk) 20:48, 10 March 2026 (UTC)

Hello, I'm Kvinnen. I noticed that you added or changed content in an article, Wear, but you didn't provide a reliable source. On Wikipedia, it's important that article content be verifiable. If you'd like to resubmit your change with a citation, your edit is archived in the page history. If you have any questions, you can leave me a message on my talk page. Thank you. _signed, Kvinnen (talk) 20:30, 11 March 2026 (UTC)

Thank you for the clarification. I will try to improve my edits by ensuring they are more closely aligned with section topics and supported by high-quality sources. Materials Engineer1 (talk) 17:55, 20 March 2026 (UTC)

Please refrain from making unconstructive edits to Wikipedia, as you did at Tribology. Your edits appear to be disruptive and have been or will be reverted.

• If you are engaged in an article content dispute with another editor, please discuss the matter with the editor at their talk page, or the article's talk page, and seek consensus with them. Alternatively, you can read Wikipedia's dispute resolution page, and ask for independent help at one of the relevant noticeboards.
• If you are engaged in any other form of dispute that is not covered on the dispute resolution page, please seek assistance at Wikipedia's Administrators' noticeboard/Incidents.

Please ensure you are familiar with Wikipedia's policies and guidelines, and please do not continue to make edits that appear disruptive. Continued disruptive editing may result in loss of editing privileges. The latest material that you added was not on-topic for the sections that you added them to. I restored one of your prior edits which were close to off topic, and removed as refspam. These recent ones are definitely not appropriate minor additions. Ldm1954 (talk) 21:00, 19 March 2026 (UTC)