X80 pipeline steel was welded with submerged arc automatic welding, the microstructures, cavity sizes, fusion depths and plane scanning of chemical elements in the welded zone, fusion zone, heat affected zone and base...X80 pipeline steel was welded with submerged arc automatic welding, the microstructures, cavity sizes, fusion depths and plane scanning of chemical elements in the welded zone, fusion zone, heat affected zone and base steel were observed with OM（optical microscope） and SEM（scanning electron microscope）, respectively. The experimental results show that there is main acicular ferrite in the base steel and welded zone, the microscopic structure of fusion zone is a blocked bainite, and the heat affected zone is composed of multilateral ferrite and pearlite. M-A unit of the welded zone is the main factor to strengthen the welded zone, composed of acicular ferrites. The percentage of cavities in the welded joint is less than that in the base steel, which is beneficial to increasing its mechanical performance and corrosion resistance. The fusion depth in the fusion zone and welded zone is 101.13 μm and 115.85 μm, respectively, and the distribution of chemical elements in the welded zone is uniform, no enrichment phenomena.展开更多
The sensitization behavior of special structures such as weld seams reduces the resistance of materials to intergranular corrosion and intergranular stress corrosion cracking. How ever,the degree of sensitization in t...The sensitization behavior of special structures such as weld seams reduces the resistance of materials to intergranular corrosion and intergranular stress corrosion cracking. How ever,the degree of sensitization in the seams could not be detected by the traditional electrochemical potentiokinetic reactivation（ EPR） measurement using the double loop method. Results based on non-effective tests bring risks to the application of these materials. In this study,the degree of sensitization in w eld seams are determined by using the scanning vibrating probe（ SVP）method.展开更多
基金Funded by the Chief Expert (Engineer) Project of Jiangsu Provincial Association for Science(No.2013-216)the Innovation Program of Graduated Student of Jiangsu Province(CXLX2014-1098)
文摘X80 pipeline steel was welded with submerged arc automatic welding, the microstructures, cavity sizes, fusion depths and plane scanning of chemical elements in the welded zone, fusion zone, heat affected zone and base steel were observed with OM（optical microscope） and SEM（scanning electron microscope）, respectively. The experimental results show that there is main acicular ferrite in the base steel and welded zone, the microscopic structure of fusion zone is a blocked bainite, and the heat affected zone is composed of multilateral ferrite and pearlite. M-A unit of the welded zone is the main factor to strengthen the welded zone, composed of acicular ferrites. The percentage of cavities in the welded joint is less than that in the base steel, which is beneficial to increasing its mechanical performance and corrosion resistance. The fusion depth in the fusion zone and welded zone is 101.13 μm and 115.85 μm, respectively, and the distribution of chemical elements in the welded zone is uniform, no enrichment phenomena.
文摘The sensitization behavior of special structures such as weld seams reduces the resistance of materials to intergranular corrosion and intergranular stress corrosion cracking. How ever,the degree of sensitization in the seams could not be detected by the traditional electrochemical potentiokinetic reactivation（ EPR） measurement using the double loop method. Results based on non-effective tests bring risks to the application of these materials. In this study,the degree of sensitization in w eld seams are determined by using the scanning vibrating probe（ SVP）method.
