In this paper, through the data treatment of correlation coefficients and the clustering technique of pattern recognition, both the matrix of correlation coefficients and the pedigree of factor clusters show that some...In this paper, through the data treatment of correlation coefficients and the clustering technique of pattern recognition, both the matrix of correlation coefficients and the pedigree of factor clusters show that some factors affecting soil corrosivity are interrelated closely, and some independent relatively. The data analytical method used in this paper has certain assistance to the selection of major soil factors during the prediction and evaluation of soil corrosivity.展开更多
The microstructure of welded joint is surveyed and the mechanical properties of X65 pipeline steel are studied in this paper, which provides experimental basis of performance effect on stress corrosion. H 2S stress co...The microstructure of welded joint is surveyed and the mechanical properties of X65 pipeline steel are studied in this paper, which provides experimental basis of performance effect on stress corrosion. H 2S stress corrosion cracking (SCC) tests on the steel are carried out in the environment based on NACE TM- 01-77 solution. The threshold stress intensity factor and crack propagation velocity for base metal and HAZ are obtained. The susceptibility of welded joint for X65 pipeline steel to H 2S stress corrosion cracking is investigated. The programming package ANSYS of finite element model (FEM) is used to perform the three-dimensional elastic-plastic finite element analysis of WOL specimens. Stress field and concentration of hydrogen distribution property of the crack tip are obtained.展开更多
The susceptibility of welded joint for the X65 pipeline steel to H_2S stress corrosion cracking (SCC) is investigated. SCC tests on the steel are carried out in the environment based on NACE TM-01-77 solution with sat...The susceptibility of welded joint for the X65 pipeline steel to H_2S stress corrosion cracking (SCC) is investigated. SCC tests on the steel are carried out in the environment based on NACE TM-01-77 solution with saturated gaseous H_2S. The threshold stress intensity factor and crack propagation velocity are calculated according to wedge-opening loading (WOL) specimens. The three-dimensional elastic-plastic finite element analysis of WOL specimens is performed by using the FEM programming package ANSYS. Stress field and concentration of hydrogen distribution property ahead of the crack tip are obtained. This paper surveyed the microstructure of welded joint and studied on the mechanical properties of X65 pipeline steel. It provides experimental basis for studying stress corrosion. The results of numerical analysis are consistent with conclusions of stress corrosion test.展开更多
A new kind of bittern-resisting cement （BRC） was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 S phase, high-activity ground granulated blast-furnace slag （GGBFS）...A new kind of bittern-resisting cement （BRC） was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 S phase, high-activity ground granulated blast-furnace slag （GGBFS） and fly ash （FA）. The hydration process and the hydrated products of BRC were studied by means of XRD, TG-DTA and SEM, and the resistance to chemical attack of BRC in high-bittern environment was also examined. The corrosion experiment in seven kinds of brines proved that BRC exhibits an excellent resistance to chemical attack of bittern. The corrosion resistance factors were calculated and all of them were greater than 0.96. It showed that BRC totally controls the cement-based material corrosion in brines from four aspects： （1） making full use of the dominant complementation effect of mineral materials; （2） diminishing the hydrated products easy to be attacked; （3） improving the microstructure of hardened cement mortar; （4） degrading the chemical attack of bittern.展开更多
文摘In this paper, through the data treatment of correlation coefficients and the clustering technique of pattern recognition, both the matrix of correlation coefficients and the pedigree of factor clusters show that some factors affecting soil corrosivity are interrelated closely, and some independent relatively. The data analytical method used in this paper has certain assistance to the selection of major soil factors during the prediction and evaluation of soil corrosivity.
文摘The microstructure of welded joint is surveyed and the mechanical properties of X65 pipeline steel are studied in this paper, which provides experimental basis of performance effect on stress corrosion. H 2S stress corrosion cracking (SCC) tests on the steel are carried out in the environment based on NACE TM- 01-77 solution. The threshold stress intensity factor and crack propagation velocity for base metal and HAZ are obtained. The susceptibility of welded joint for X65 pipeline steel to H 2S stress corrosion cracking is investigated. The programming package ANSYS of finite element model (FEM) is used to perform the three-dimensional elastic-plastic finite element analysis of WOL specimens. Stress field and concentration of hydrogen distribution property of the crack tip are obtained.
文摘The susceptibility of welded joint for the X65 pipeline steel to H_2S stress corrosion cracking (SCC) is investigated. SCC tests on the steel are carried out in the environment based on NACE TM-01-77 solution with saturated gaseous H_2S. The threshold stress intensity factor and crack propagation velocity are calculated according to wedge-opening loading (WOL) specimens. The three-dimensional elastic-plastic finite element analysis of WOL specimens is performed by using the FEM programming package ANSYS. Stress field and concentration of hydrogen distribution property ahead of the crack tip are obtained. This paper surveyed the microstructure of welded joint and studied on the mechanical properties of X65 pipeline steel. It provides experimental basis for studying stress corrosion. The results of numerical analysis are consistent with conclusions of stress corrosion test.
基金This work was financially supported by the Key Scientific and Technological Project of Qinghai Province (No.2002-G-103)
文摘A new kind of bittern-resisting cement （BRC） was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 S phase, high-activity ground granulated blast-furnace slag （GGBFS） and fly ash （FA）. The hydration process and the hydrated products of BRC were studied by means of XRD, TG-DTA and SEM, and the resistance to chemical attack of BRC in high-bittern environment was also examined. The corrosion experiment in seven kinds of brines proved that BRC exhibits an excellent resistance to chemical attack of bittern. The corrosion resistance factors were calculated and all of them were greater than 0.96. It showed that BRC totally controls the cement-based material corrosion in brines from four aspects： （1） making full use of the dominant complementation effect of mineral materials; （2） diminishing the hydrated products easy to be attacked; （3） improving the microstructure of hardened cement mortar; （4） degrading the chemical attack of bittern.
