scholarly journals Effects of Rare Earth (Ce and La) on Steel Corrosion Behaviors under Wet-Dry Cycle Immersion Conditions

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1174
Author(s):  
Xintong Lian ◽  
Jianan Zhu ◽  
Ruiqian Wang ◽  
Tengshi Liu ◽  
Jing Xu ◽  
...  

Rare earth (RE) elements are beneficial to improving corrosion properties in low-carbon and low-alloy steels. In this paper, corrosion performance of Q235B steel and Q355B steel samples after RE alloying under wet-dry cycle immersion conditions were analyzed. Experimental results show that corrosion rate was significantly decreased. It was probably due to the grain refinement by RE alloying, which increased the density of protective rust layers and improved corrosion resistance. The formation of small-sized spherical RE inclusions also inhibited the precipitation of MnS and weakened micro galvanic corrosion. Additionally, RE atoms tended to segregate towards grain boundaries and a RE concentration region is formed between rust layers and matrix to impede the access from contacting corrosive ions. A corrosion resistance schematic of RE atom segregation was proposed based on microstructure morphology and element distribution results.

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Harsisto .

Research-based characterization of low alloy steel chrome andmanganese is done because of the problem of corrosion and corrosion limit water evenly on low carbon steel. Based on the findings, the engine coolant is switched on-and off every day so there was influence of outside air and the decrease of the temperature to room temperature. Based on the research and discussion of the characteristics of the five types low alloy steel containing 0.5 wt% manganese in the medium 60% LiBr + 0.2% LiOH at a temperature of (150 ± 2) ° C and exposure to atmospheric air for 50 hours and 110 hours , it showed that the corrosion rate is dependent on the level of content of the chromium. In the addition of the chromium in low alloy steels exposed in the test solution, there is no consistency in the natural corrosion potential value, but in general all test objects were in a corroded state.Keywords : air conditioner, low alloy steel, corrosion, LiBr, LiOH, the boiling temperature and the room temperature.AbstrakPenelitian karakterisasi baja paduan rendah berbasis krom dan mangan ini dilakukan karena adanya masalah korosi merata dan korosi batas air pada baja karbon rendah. Berdasar fakta di lapangan,mesin pendingin tersebut dilakukan “on-Off” setiap hari sehingga ada pengaruh udara luar dan turunnya suhu hingga suhu ruangan. Berdasarkan penelitian dan pembahasan tentang karakteristik 5 jenis baja paduan rendah dengan kandungan 0,5% berat unsur mangan dalam media 60% LiBr + 0,2% LiOH pada suhu(150±2) °C dan ekspos udara atmosfer selama 50 jam dan 110 jam, hasilnya menunjukkan bahwa laju korosi masih tergantung pada kadar kandungan unsur krom. Pada penambahan unsur krom dalam baja paduan rendah yang diekspos dalam larutan uji, tidak menunjukkan adanya konsistensi harga potensial korosi alaminya, tetapi secara umum semua benda uji berada dalam keadaanterkorosi.Kata Kunci : mesin pendingin ruangan, baja paduan rendah, korosi, LiBr,LiOH, suhu didih dan suhu ruangan.AbstrakPenelitian karakterisasi baja paduan rendah berbasis krom dan mangan inidilakukan karena adanya masalah korosi merata dan korosi batas air padabaja karbon rendah.Berdasar fakta di lapangan,mesin pendingin tersebut dilakukan “on-Off” setiaphari sehingga ada pengaruh udara luar dan turunnya suhu hingga suhuruangan. Berdasarkan penelitian dan pembahasan tentang karakteristik 5jenis baja paduan rendah dengan kandungan 0,5% berat unsur mangandalam media 60% LiBr + 0,2% LiOH pada suhu(150±2) °C dan ekspos udaraatmosfer selama 50 jam dan 110 jam, hasilnya menunjukkan bahwa lajukorosi masih tergantung pada kadar kandungan unsur krom. Padapenambahan unsur krom dalam baja paduan rendah yang diekspos dalamlarutan uji, tidak menunjukkan adanya konsistensi harga potensial korosialaminya, tetapi secara umum semua benda uji berada dalam keadaanterkorosi.Kata Kunci : mesin pendingin ruangan, baja paduan rendah, korosi, LiBr,LiOH, suhu didih dan suhu ruangan.


Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3686 ◽  
Author(s):  
Jing Ren ◽  
Enyu Guo ◽  
Xuejian Wang ◽  
Huijun Kang ◽  
Zongning Chen ◽  
...  

In this paper, the microstructures and corrosion behaviors of as-cast Mg–5Sn–xGa alloys with varying Ga content (x = 0, 0.5, 1, 2, 3 wt %) were investigated. The results indicated that Ga could not only adequately refine the grain structure of the alloys, but could also improve the corrosion resistance. The microstructures of all alloys exhibited typical dendritic morphology. No Ga-rich secondary phases were detected when 0.5 wt % Ga was added, while only the morphology of Mg2Sn phase was changed. However, when the addition rate of Ga exceeded 0.5 wt %, an Mg5Ga2 intermetallic compound started to form from the interdendritic region. The volume fraction of Mg5Ga2 monotonically increased with the increasing Ga addition level. Although Mg5Ga2 phase was cathode phase, its pitting sensitivity was weaker than Mg2Sn. In addition, the standard potential of Ga (−0.55 V) was lower than that of Sn (−0.14 V), which relieved the driving force of the secondary phases for the micro-galvanic corrosion. An optimized composition of 3 wt % Ga was concluded based on the immersion tests and polarization measurements, which recorded the best corrosion resistance.


Alloy Digest ◽  
2020 ◽  
Vol 69 (12) ◽  

Abstract Outokumpu Moda 410L/4003 is a weldable, extra low carbon, Cr-Ni, ferritic stainless steel that is best suited for mildly corrosive environments such as indoors, where the material is either not exposed to contact with water or gets regularly wiped dry, or outdoors, where some discoloration and superficial rusting are acceptable. It is a low-cost alternative to low-carbon non-alloy steels in certain applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1330. Producer or source: Outokumpu Oyj.


Alloy Digest ◽  
1983 ◽  
Vol 32 (8) ◽  

Abstract TRI-MARK TM-115 is a gas-shielded flux-cored welding electrode for continuous high deposition are welding. It is designed specifically for semiautomatic and automatic arc welding of high-strength low-alloy steels and quenched-and-tempered steels. This gas-sheilded tubular wire can be used for single and multiple-pass welding. It has outstanding low-temperature impact properties. Its applications including mining equipment, large vehicles and similar items. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-392. Producer or source: Tri-Mark Inc..


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3071
Author(s):  
Andri Isak Thorhallsson ◽  
Francesco Fanicchia ◽  
Emily Davison ◽  
Shiladitya Paul ◽  
Svava Davidsdottir ◽  
...  

Geothermal process equipment and accessories are usually manufactured from low-alloy steels which offer affordability but increase the susceptibility of the materials to corrosion. Applying erosion-corrosion-resistant coatings to these components could represent an economical solution to the problem. In this work, testing of two newly developed laser metal deposited high-entropy alloy (LMD-HEA) coatings—CoCrFeNiMo0.85 and Al0.5CoCrFeNi, applied to carbon and stainless steels—was carried out at the Hellisheidi geothermal power plant. Tests in three different geothermal environments were performed at the Hellisheidi site: wellhead test at 194 °C and 14 bar, erosion test at 198 °C and 15 bar, and aerated test at 90 °C and 1 bar. Post-test microstructural characterization was performed via Scanning Eletron Microscope (SEM), Back-Scattered Electrons analysis (BSE), Energy Dispersive X-ray Spectroscopy (EDS), optical microscopy, and optical profilometry while erosion assessment was carried out using an image and chemical analysis. Both the CoCrFeNiMo0.85 and Al0.5CoCrFeNi coatings showed manufacturing defects (cracks) and were prone to corrosion damage. Results show that damage in the CoCrFeNiMo0.85-coated carbon steel can be induced by manufacturing defects in the coating. This was further confirmed by the excellent corrosion resistance performance of the CoCrFeNiMo0.85 coating deposited onto stainless steel, where no manufacturing cracks were observed.


2017 ◽  
Vol 36 (4) ◽  
pp. 309-325 ◽  
Author(s):  
Wangzhong Mu ◽  
Pär Göran Jönsson ◽  
Keiji Nakajima

AbstractIntragranular ferrite (IGF), which nucleates from specific inclusion surfaces in low alloy steels, is the desired microstructure to improve mechanical properties of steel such as the toughness. This microstructure is especially important in the coarse grain heat affected zone (CGHAZ) of weldments. The latest review paper focusing on the role of non-metallic inclusions in the IGF formation in steels has been reported by Sarma et al. in 2009 (ISIJ int., 49(2009), 1063–1074). In recent years, large amount of papers have been presented to investigate different issues of this topic. This paper mainly highlights the frontiers of experimental and theoretical investigations on the effects of inclusion characteristics, such as the composition, size distribution and number density, on the IGF formation in low carbon low-alloyed steels, undertaken by the group of Applied Process Metallurgy, KTH Royal Institute of Technology. Related results reported in previous studies are also introduced. Also, plausible future work regarding various items of IGF formation is mentioned in each section. This work aims to give a better control of improving the steel quality during casting and in the heat affected zone (HAZ) of weldment, according to the concept of oxide metallurgy.


Alloy Digest ◽  
2021 ◽  
Vol 70 (6) ◽  

Abstract AK Steel 409 Ni is a 11% chromium ferritic stainless steel microalloyed with titanium and nickel. It provides excellent weldability, toughness, and fabricating characteristics superior to those of type 409 stainless steel in thicknesses over 3.05 mm (0.120 in.). This alloy is a cost effective alternative to mild steels and low-alloy steels that also provides superior corrosion and/or oxidation resistance. The recommended maximum service temperature of AK Steel 409 Ni is 730 °C (1350 °F). This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating and joining. Filing Code: SS-1336. Producer or source: AK Steel Corporation.


2019 ◽  
Vol 71 (2) ◽  
pp. 258-266 ◽  
Author(s):  
Zheng Liu ◽  
Xintong Lian ◽  
Tengshi Liu ◽  
Yudan Yang ◽  
Jianan Zhu ◽  
...  

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