Quantitative Modeling for Corrosion Behavior in Complex Coupled Environment by Response Surface Methodology

Abstract

Response surface methodology (RSM) is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion prediction in complex coupled environment (CCE). In this study, a typical CCE, that is, the corrosion environment of pipelines in gas field is taken as an example. The effects of environmental factors such as chloride concentration, pH value and pressure as well as their interactions on critical pitting temperature (CPT) were evaluated, and a quadratic polynomial model was developed for corrosion prediction by RSM. The results showed that the model was excellent in corrosion prediction with R 2 = 0.9949. CPT was mostly affected by single environmental factor rather than interaction, and among the whole factors, chloride concentration was the most influential factor of CPT.

Microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel

“…Mn element in the solution state bring about an important influence on the transformation of supercooling austenite, one aspect, it changes the free energy difference of the new and old phases, alters the critical temperature of phase transition, and causes different extents of moving up and down of pearlite transformation curve and bainite transformation curve; the other aspect, C and Mn are elements to stabilize the austenite, Mn element also increases the diffusion activation energy of C element in austenite, thus they affect the nucleation and growth process of pearlite transformation and bainite transformation, and cause different extents of moving to the right of pearlite transformation curve and bainite transformation curve. Due to the movement of these two transformations curve, the C curve of C-Mn segregation region exists the bay-like shape [21] , which is the separation of pearlite transformation and bainite transformation, as shown in Fig.10. Therefore, the transformation process of supercooling austenite at the center of steel plate may pass through bainite transformation region at relatively lower cooling rate (8℃/s).…”

The development of a mechanistic-chemometrics model with multi-degree of freedom for pitting corrosion of HP-13Cr stainless steel under extremely oilfield environments

“…This method is based on the decomposition of total variability in the selected response (y) and assesses the relationship between the factors and the variability of responses. The significant factors or interactions can be identified as the ratio of the mean square of a factor or as an interaction and the residual mean square (F-value) [49][50]. If the F-value was less than 11.27, the factors were considered as negligible [55].…”

“…In addition, chemometrics method belongs to a discipline that provides an efficient approach through statistical or mathematical methods to investigate the effect of each variable and the interaction between variables [48][49][50]. A combination of chemometric method and the model proposed by Zhang's group results in a novel mechanistic-chemometric prediction model, which is developed herein in order to incorporate the influence of temperature, CO2 pressure, flow rate and stress on the growth kinetics of pits.…”

Effect of the calcareous deposits on the cathodic protection potential of 10Ni5CrMoV high‐strength steel in a deep‐sea environment by using the response surface methodology

“…Besides this, F I G U R E 8 Surface morphology, cross-section morphology and thickness of the calcareous deposits at various pressure of the deep-sea environment the properties of the calcareous deposits including the porosity, Ca/Mg ratio and the TH are also determined by the T, P, and DO. Thus, mapping relationships between the properties of the calcareous deposit and the CP potential of the steel covered with the calcareous deposit could be established, and the results are shown as Equations (16) and (17). Furthermore, this was combined with our previous work, [31,32] which investigated the effect of environmental factors on CP potentials of 10Ni5CrMoV steel.…”

“…Response surface methodology (RSM) using statistical methods provides an efficient approach to explore the effect of individual factors and interactions to optimize the system and has been widely used in many engineering fields, such as material engineering, [16] food engineering, [17] and chemical engineering. [18][19][20][21] Goh et al used RSM to evaluate the dosage, pH value, and contact time effects of high-dose phosphate inhibition for copper corrosion control.…”