A separation phenomenon occurring during the drop weight tear test of commercial thick-walled API （American Petroleum Institute） X80 strip steel was investigated in this work. Microstructural analysis showed that th...A separation phenomenon occurring during the drop weight tear test of commercial thick-walled API （American Petroleum Institute） X80 strip steel was investigated in this work. Microstructural analysis showed that the band structure of bainite elongated along the rolling direction works as the initiation sites of separation. The propagation of separation can be promoted not only by the occurrence of the band structure of martensite/austenite constituent, prior austenite grain boundaries, and elongated bainite, but also by fine acicular ferrite and bainite. Wide separation formed in the former case, while the narrow one appeared in the latter case. acicular ferrite in thick-walled X80 pipeline steel in order Some methods were proposed to obtain fine and homogeneous to minimize the occurrence of separation.展开更多
对比了API RP 5L3—2014与SY/T 6476—2013标准中落锤撕裂试验的适用范围、试样制备、设备参数、试验温度和试样评价等主要技术要求。分析认为:这两个标准在落锤撕裂试验取样位置、试验尺寸、试样保温条件和试验结果评定方面存在较大差...对比了API RP 5L3—2014与SY/T 6476—2013标准中落锤撕裂试验的适用范围、试样制备、设备参数、试验温度和试样评价等主要技术要求。分析认为:这两个标准在落锤撕裂试验取样位置、试验尺寸、试样保温条件和试验结果评定方面存在较大差异;API RP 5L3—2014只适用于管线钢管,对试样缺口半径尺寸要求较为宽松,保温介质为液体,不接受异常断口的评定;SY/T 6476—2013适用于管线钢管和制管用板卷、钢板,对试样缺口半径要求严格,保温介质为液体或气体,规范性附录B中规定了异常断口的评定方法。展开更多
综述了按GB/T 8363与API RP 5L3等标准所执行的铁素体钢落锤撕裂试验(DWTT)技术的发展概况及其在评价高强度、高韧性金属材料动态断裂性能,特别是在韧断止裂性能中的应用,如高等级管线钢、压力容器用钢以及高止裂性能船板用钢等。具体而...综述了按GB/T 8363与API RP 5L3等标准所执行的铁素体钢落锤撕裂试验(DWTT)技术的发展概况及其在评价高强度、高韧性金属材料动态断裂性能,特别是在韧断止裂性能中的应用,如高等级管线钢、压力容器用钢以及高止裂性能船板用钢等。具体而言,第一代DWTT试验机具有较高打击能量冲断试样暴露断裂面,仅用于评价设定温度断口剪切面积分数pSA指标;第二代试验机可实测试样的DWTT吸收能,是夏比冲击技术在大尺寸试样与实物性能评测中的重要拓展;第三代试验机具备仪器化测力分析功能,可结合弹塑性断裂力学原理开展动态断裂性能评价,特别是评估管线钢的临界裂纹尖端张开角度指标,即ψCTOA,c。展开更多
文摘A separation phenomenon occurring during the drop weight tear test of commercial thick-walled API （American Petroleum Institute） X80 strip steel was investigated in this work. Microstructural analysis showed that the band structure of bainite elongated along the rolling direction works as the initiation sites of separation. The propagation of separation can be promoted not only by the occurrence of the band structure of martensite/austenite constituent, prior austenite grain boundaries, and elongated bainite, but also by fine acicular ferrite and bainite. Wide separation formed in the former case, while the narrow one appeared in the latter case. acicular ferrite in thick-walled X80 pipeline steel in order Some methods were proposed to obtain fine and homogeneous to minimize the occurrence of separation.
文摘对比了API RP 5L3—2014与SY/T 6476—2013标准中落锤撕裂试验的适用范围、试样制备、设备参数、试验温度和试样评价等主要技术要求。分析认为:这两个标准在落锤撕裂试验取样位置、试验尺寸、试样保温条件和试验结果评定方面存在较大差异;API RP 5L3—2014只适用于管线钢管,对试样缺口半径尺寸要求较为宽松,保温介质为液体,不接受异常断口的评定;SY/T 6476—2013适用于管线钢管和制管用板卷、钢板,对试样缺口半径要求严格,保温介质为液体或气体,规范性附录B中规定了异常断口的评定方法。
文摘综述了按GB/T 8363与API RP 5L3等标准所执行的铁素体钢落锤撕裂试验(DWTT)技术的发展概况及其在评价高强度、高韧性金属材料动态断裂性能,特别是在韧断止裂性能中的应用,如高等级管线钢、压力容器用钢以及高止裂性能船板用钢等。具体而言,第一代DWTT试验机具有较高打击能量冲断试样暴露断裂面,仅用于评价设定温度断口剪切面积分数pSA指标;第二代试验机可实测试样的DWTT吸收能,是夏比冲击技术在大尺寸试样与实物性能评测中的重要拓展;第三代试验机具备仪器化测力分析功能,可结合弹塑性断裂力学原理开展动态断裂性能评价,特别是评估管线钢的临界裂纹尖端张开角度指标,即ψCTOA,c。
