Heat-Resistant Steels, Microstructure Evolution and Life Assessment in Power Plants

Hu, Zhang

doi:10.5772/26766

Cited by 20 publications

(11 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The P11 (or Grade 11; also denoted as 13CrMo4-5 or 13CrMo44 or 1½ Cr-½ Mo or 1.25Cr-0.5Mo) pipe material is a seamless heat-resistant steel alloy commonly used in the power industry, petrochemical plants, refineries and oil and gas fields where it is usually used in applications (among others) such as superheater tubes, steam lines and headers and can be continuously used to about 560°C wall temperatures. It belongs to the ASTM A335 chromium-molybdenum low alloy steels family (referred also as chrome-moly or Cr-Mo steels), with a ferritic matrix and dark pearlite regions (ASTM International, 2015;Hu, 2012;Bahri, 2017;Hajiannia et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…Several failure studies have been carried out on heat-resistant alloy piping materials used in applications such as, among many others, power plants, preheater tubes of heat recovery boilers and superheaters (Hu, 2012;Bahri, 2017;Hajiannia et al, 2014;Chownanonthapunya and Joipadrit, 2017;Hajri et al, 2015;Dudziak, 2016;Raman and Al-Mazrouee, 2007;Sabouri and Faridi, 2017;Saha and Roy, 2017). In particular, some works, related to corrosion failure analysis in grade pipe steel alloy materials and in other alloys, out of thousands performed, have been reported (Chownanonthapunya and Joipadrit, 2017;Raman and Al-Mazrouee, 2007;Sabouri and Faridi, 2017;Aperadora et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Corrosion of a chrome-moly pipe transporting sulfuric acid in a demineralization section: a failure analysis

Márquez¹,

Maharaj

2021

ACMM

View full text Add to dashboard Cite

Purpose The purpose of this study was to carry out an analysis of the corrosion failure on a chrome-moly pipeline transporting highly concentrated sulfuric acid in a demineralization section at a petrochemical plant, along with the feasibility of using inhibitors to minimize the corrosive effects of sulfuric acid. Design/methodology/approach X-ray fluorescence spectroscopy, high-resolution optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and accelerated corrosion experiments (ACE) were performed. Findings Erosion-corrosion failure was confirmed by the significant reduction in thickness of the internal surface of the material exposed to sulfuric acid, as well as the formation of an oxide scale/layer. ACE accurately predicted high material loss from exposure to sulfuric acid. Moreover, adding ascorbic acid as a corrosion inhibitor (even at low concentrations) was found to reduce the oxidation by more than 50% in the presence of sulfuric acid. Originality/value The main idea/purpose of this work relies on the analysis of recurrent real-life corrosion-attributed failures that are common in industry but are not properly addressed for a variety of reasons, poor management and lack of corrosion preventive strategies being the main ones. This study once again highlights readily available solutions/implementations that are capable of not only addressing technically the issue investigated but also, and as important, economically. By using microscopic imaging, reliable well-tested and widely used characterization methods, all combined with basic experiments and tests, the nature of the repetitive failure investigated was clearly demonstrated as well as readily available alternatives to minimize it in the short term. Nevertheless, implementing material selection techniques appropriately as effective corrosion prevention/control and cost-saving strategies must be enforced in any process.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Corrosion of a chrome-moly pipe transporting sulfuric acid in a demineralization section: a failure analysis

Márquez¹,

Maharaj

2021

ACMM

View full text Add to dashboard Cite

show abstract

“…Increasing of thermal efficiency minimizes the fuel consumption and emissions of environmentally damaging gases. In order to enhance the thermal efficiency, there is a need for increasing the operating temperatures and pressures, which demands use of creep strength enhanced ferritic (CSEF) steels for constructing parts of advanced power plants [1][2][3]. The P91 and P92 martensitic steels are prominent for high-temperature application.…”

Section: Introductionmentioning

confidence: 99%

Optimal laser welding process parameters and expected weld bead profile for P92 steel

2019

View full text Add to dashboard Cite

P92 steel is classified as one of the creep strength enhanced ferritic steels, whose welding plays a crucial role in power industries. The best choice for such materials is the laser welding in open atmosphere with an inert gas shield. Compared to the frequently being used Taguchi based grey relational analysis, a simple and systematic approach known as the modified Taguchi design of experiments is utilized for P92 steel to obtain the optimized laser welding process parameters and the expected range of output responses. The complicated non-linear relationship between the laser welding process parameters (viz., laser power, welding speed and focal position) and the welding bead geometry (such as depth of penetration, weld width and heat affected zone width) is developed through empirical relations, which are validated by comparing with existing test results. Most of the test results are found to be within the expected range. From the ANOVA analysis the process parameter, viz. the focal position is found to have negligible variation on the overall mean value of the output responses and hence, the process designer can opt for any one the set levels of the focal position during welding operations.

show abstract

“…A peak separation technique was used to separate the (111) γ -reflection from the overlapping (110) α -reflection. Retained austenite was determined by method of direct comparison (Averbach-Cohen method) using the formula: (1) where:…”

Section: Methodsmentioning

confidence: 99%

“…Typically Cr-Mo steels are intended for boiler tubes, wire pairs, parts of boilers and steam turbines, components and other equipment operating at temperatures up to 580 o C [1]. The first Cr-Mo steels were used for conventional power-generation applications in the 1920s.…”

Section: Introductionmentioning

confidence: 99%

Bainitic reaction and microstructure evolution in two normalized and tempered steels designed for service at elevated temperatures

Ławrynowicz

2017

Advances in Materials Science

View full text Add to dashboard Cite

In the present work conventional heat treatment like normalizing (bainitic microstructure) and tempering of the alloys has been performed. The materials used in this study were two steels, one the laboratory prepared experimental low alloy Cr-Mo steel in comparison to typical commercial 10CrMo9-10 steel. The determined carbon concentrations of the residual austenite at the different temperatures of bainite transformation supports the hypothesis that the growth of bainitic ferrite occurs without any diffusion with carbon being partitioned subsequently into the residual austenite. It was found that bainitic reaction has stopped when average carbon concentration of the untransformed austenite is close to the T 0 line and supports formation of bainitic ferrite by a shear mechanism, since diffusionless transformation is not possible beyond the T 0 curve. Normalized samples were air cooled down to room temperature before tempering at various temperatures in the range of 500-750 o C. Samples have been austenitized at 980 o C for 0.5 hour air cooled and tempered at 500, 550, 600, 650, 700 and 750 o C for 1 hour. After heat treatment, the assessment in the microstructure and phase precipitation was made using the samples prepared for metallographic and transmission electron microscope (TEM) on thin foils analysis. Quantitative X-ray analysis was used to determine the retained austenite content after heat treatment like normalizing and tempering and the total volume fraction of the retained austenite was measured from the integral intensity of the (111) γ and (011) α peaks. The changes observed in the microstructure of the steel tempered at the higher temperature, i.e. 750°C were more advanced than those observed at the temperature of 500°C. Performed microstructural investigations have shown that the degradation of the microstructure of the examined steel was mostly connected with the processes of recovery and polygonization of the matrix, disappearance of lath bainitic microstructure, the growth of the size of M 23 C 6 carbides, and precipitation of the secondary M 2 C precipitates. The magnitude of these changes depended on the temperature of tempering.

show abstract

Heat-Resistant Steels, Microstructure Evolution and Life Assessment in Power Plants

Cited by 20 publications

References 44 publications

Corrosion of a chrome-moly pipe transporting sulfuric acid in a demineralization section: a failure analysis

Corrosion of a chrome-moly pipe transporting sulfuric acid in a demineralization section: a failure analysis

Optimal laser welding process parameters and expected weld bead profile for P92 steel

Bainitic reaction and microstructure evolution in two normalized and tempered steels designed for service at elevated temperatures

Contact Info

Product

Resources

About