In this study, the welding technology of the hot-rolled extra-high-strength steel, BS960QC, has been comprehensively investigated. Analysis has been made on the weldability ,the different welding procedures ,the mecha...In this study, the welding technology of the hot-rolled extra-high-strength steel, BS960QC, has been comprehensively investigated. Analysis has been made on the weldability ,the different welding procedures ,the mechanical properties, and the fatigue properties, and a set of recommendation guidelines have been proposed for evaluating the welded joints of the extra-high-strength steel. The research and results indicate that the hot-rolled extra-high-strength steel, BS960QC,has good weldability and an excellent adaptability to welding procedures. Further,the excellent mechanical properties and fatigue properties of the welded joints ,which can be achieved by using optimized welding procedures, can completely meet the technical requirements of the construction machinery industry.展开更多
Using the Gleeble 3500 thermal-mechanical system to simulate thermal cycles with different peak temperatures, the hardness and microstructure in the heat-affected zones of two kinds of 100 kg class hot-rolled extra-hi...Using the Gleeble 3500 thermal-mechanical system to simulate thermal cycles with different peak temperatures, the hardness and microstructure in the heat-affected zones of two kinds of 100 kg class hot-rolled extra-high-strength steel were compared. When the peak temperature of the thermal cycle was 800℃ ,incomplete transformation occurred during quenching in both steels, and massive martensite and bainite grains were formed. The hardness was determined by the composition and distribution of the microstructure. The concentration of massive martensite was low, and hence the hardness was low,in steel #1. Conversely,the massive martensite content in steel #2 was high and uniformly distributed,resulting in a high hardness. These findings can provide a reference for improving the mechanical properties in the softened zone.展开更多
文摘In this study, the welding technology of the hot-rolled extra-high-strength steel, BS960QC, has been comprehensively investigated. Analysis has been made on the weldability ,the different welding procedures ,the mechanical properties, and the fatigue properties, and a set of recommendation guidelines have been proposed for evaluating the welded joints of the extra-high-strength steel. The research and results indicate that the hot-rolled extra-high-strength steel, BS960QC,has good weldability and an excellent adaptability to welding procedures. Further,the excellent mechanical properties and fatigue properties of the welded joints ,which can be achieved by using optimized welding procedures, can completely meet the technical requirements of the construction machinery industry.
文摘Using the Gleeble 3500 thermal-mechanical system to simulate thermal cycles with different peak temperatures, the hardness and microstructure in the heat-affected zones of two kinds of 100 kg class hot-rolled extra-high-strength steel were compared. When the peak temperature of the thermal cycle was 800℃ ,incomplete transformation occurred during quenching in both steels, and massive martensite and bainite grains were formed. The hardness was determined by the composition and distribution of the microstructure. The concentration of massive martensite was low, and hence the hardness was low,in steel #1. Conversely,the massive martensite content in steel #2 was high and uniformly distributed,resulting in a high hardness. These findings can provide a reference for improving the mechanical properties in the softened zone.
