对某钻井平台用钢的2批同一焊接工艺不同工艺参数的焊接接头进行了低温CTOD韧度试验。试验结果表明:2批焊接接头的韧度都不满足标准BS7448Part2和Offshore Standard DNV-OS-C401的要求,但2批焊接接头的韧度又有所不同。针对这种情况,分...对某钻井平台用钢的2批同一焊接工艺不同工艺参数的焊接接头进行了低温CTOD韧度试验。试验结果表明:2批焊接接头的韧度都不满足标准BS7448Part2和Offshore Standard DNV-OS-C401的要求,但2批焊接接头的韧度又有所不同。针对这种情况,分别对,批焊接接头进行了金相试验,并分析了这2批焊接接头韧度存在差异的原因。得到如下结论:对于本文所论述的焊接工艺,适当减小焊接热输入可以提高焊缝中心的韧度,但对熔合线处的韧度并无明显影响。展开更多
Railway steel bridge belongs to large-scale weld structures suffered with cyclic dynamic stress generated by the train. In recent years, the section of bridge member becomes bigger, plate becomes thicker, connection f...Railway steel bridge belongs to large-scale weld structures suffered with cyclic dynamic stress generated by the train. In recent years, the section of bridge member becomes bigger, plate becomes thicker, connection form becomes more complicated and steel bridge is applied to wider districts even in the lower temperature environment. Thus, fatigue and fracture problems become more serious. On the basis of CTOD (crack tip open displacement) test data of 372 specimens tested in different temperatures, this paper discusses research work about fracture proof design that involves how to determine the criterion of CVN (Charpy V-notch) impact toughness by establishing the relationship between CTOD and CVN, how to prevent from brittle fracture by stress control in railway steel bridge design based on COD (crack open displacement) design curve through the test data and how to do the fatigue design for railway steel bridge at -50 ℃ of design temperature in an easy way. The method of fatigue design at -50 ℃ environment has been used for railway steel bridge structure of Qinghai-Tibet Railway in China.展开更多
以船用A36钢板为试验材料,开展紧凑拉伸试验裂纹尖端张开位移δ(crack tip opening displacement,CTOD)的双引伸计测试方法研究。结果显示,采用双引伸计方法可直接测定旋转因子r及δ,计算得到名义应力σ与裂纹尖端张开位移塑性分量δp(p...以船用A36钢板为试验材料,开展紧凑拉伸试验裂纹尖端张开位移δ(crack tip opening displacement,CTOD)的双引伸计测试方法研究。结果显示,采用双引伸计方法可直接测定旋转因子r及δ,计算得到名义应力σ与裂纹尖端张开位移塑性分量δp(plastic component of CTOD)的相关性曲线。与国标GB/T 21143—2007测试方法相比,双引伸计法对δp的测试精度更高;与EPRI(Electronic Power Research Institute)计算方法相比,双引伸计法对σ—δp关系曲线的确定更为直接可靠。展开更多
文摘对某钻井平台用钢的2批同一焊接工艺不同工艺参数的焊接接头进行了低温CTOD韧度试验。试验结果表明:2批焊接接头的韧度都不满足标准BS7448Part2和Offshore Standard DNV-OS-C401的要求,但2批焊接接头的韧度又有所不同。针对这种情况,分别对,批焊接接头进行了金相试验,并分析了这2批焊接接头韧度存在差异的原因。得到如下结论:对于本文所论述的焊接工艺,适当减小焊接热输入可以提高焊缝中心的韧度,但对熔合线处的韧度并无明显影响。
文摘Railway steel bridge belongs to large-scale weld structures suffered with cyclic dynamic stress generated by the train. In recent years, the section of bridge member becomes bigger, plate becomes thicker, connection form becomes more complicated and steel bridge is applied to wider districts even in the lower temperature environment. Thus, fatigue and fracture problems become more serious. On the basis of CTOD (crack tip open displacement) test data of 372 specimens tested in different temperatures, this paper discusses research work about fracture proof design that involves how to determine the criterion of CVN (Charpy V-notch) impact toughness by establishing the relationship between CTOD and CVN, how to prevent from brittle fracture by stress control in railway steel bridge design based on COD (crack open displacement) design curve through the test data and how to do the fatigue design for railway steel bridge at -50 ℃ of design temperature in an easy way. The method of fatigue design at -50 ℃ environment has been used for railway steel bridge structure of Qinghai-Tibet Railway in China.
文摘以船用A36钢板为试验材料,开展紧凑拉伸试验裂纹尖端张开位移δ(crack tip opening displacement,CTOD)的双引伸计测试方法研究。结果显示,采用双引伸计方法可直接测定旋转因子r及δ,计算得到名义应力σ与裂纹尖端张开位移塑性分量δp(plastic component of CTOD)的相关性曲线。与国标GB/T 21143—2007测试方法相比,双引伸计法对δp的测试精度更高;与EPRI(Electronic Power Research Institute)计算方法相比,双引伸计法对σ—δp关系曲线的确定更为直接可靠。