共查询到18条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
5.
针对新型钢包包壳材料SM490B钢,进行了室温断裂韧度、疲劳裂纹扩展速率及350℃(32作状态下,钢包包壳表面的最高温度)下的低周疲劳试验研究。结果表明,SM490B钢的强度和断裂韧度明显高于包壳曾用材料SM41A(Q235)、20g。在试验所取的应力强度因子幅值范围内,与Q235A钢和20g钢相比,SM490B钢的疲劳裂纹扩展速率较快。350℃下的低周疲劳寿命高于压力容器常用钢材16MnR钢30(1℃下的疲劳寿命。新型钢包包壳材料采用SM490B钢,可大大减少包壳开裂的可能性,提高钢包的承载能力和使用安全性,延长钢包的使用寿命。 相似文献
6.
7.
阐述了钢结构裂纹对断裂的影响,重点分析了疲劳裂纹的形成、扩展机制及焊接裂纹规律特性,说明了研究裂纹扩展规律的必要性和重要性。从而为实际工程如何提高构件疲劳性能提供参考建议。 相似文献
8.
FGH95合金高低周复合疲劳行为 总被引:4,自引:0,他引:4
为了解高周振动应力对FGH95合金低周疲劳过程的影响,对FGH95合金进行高低周复合疲劳和低周疲劳试验。试验结果表明:在低周疲劳过程中叠加的高周振动明显降低了FGH95合金的低周疲劳寿命;且叠加的高周振动应力越大,FGH95合金的低周疲劳寿命降低程度越大。宏观和体视显微镜下分析的试样断口形貌显示:断口呈平坦区和倾斜区两大部分,表面粗糙,有明显的反光小平面。最后,着重用扫描电子显微镜(SEM)分析疲劳裂纹扩展不同阶段的形貌特征,并对不同试验条件下的相同裂纹扩展阶段的裂缝形貌特征进行比较。 相似文献
9.
10.
11.
12.
《Baosteel Technical Research》2010,(Z1):123
With the development of technology for earthquake resistant,the research of the low yield point(LYP) steel which used for the fabrication of energy dissipation damper were paid more and more attention.The common studies of the low yield point steel is mainly about the performance with constant amplitude and constant frequency.The low cycle fatigue properties of low yield piont steel were studied by series of test with continuous varying amplitude and varying frequency with the materials testing system by us.The test results showed that low yield point steel of Baosteel have excellent low cycle fatigue properties,which meet the requirement for steel used for the fabrication of energy dissipation damper completely.The low cycle fatigue performance of low yield point steel of Baosteel mainly depended on the amplitude in test.And the effect of varying frequency for the low yield point steel was more less than varying amplitude. 相似文献
13.
������ ������Զ����ǿ������ ����ӦǨ 《钢铁研究学报》2015,27(6):35-39
Low cycle fatigue properties of anti-seismic HRB400 grade III reinforcing steel bar were investigated. The fatigue tests were conducted on Shimadzu servo-hydraulic testing machine. The tests were run under uniaxial tension-compression loading with total strain control. The cyclic stress response characteristics and relationship between cyclic stress and strain of the steel were measured. The strain-life data from the axial tests were used to derive suitable Coffin-Manson parameters for the test material. The scanning electron microscope (SEM) micrographs reveal that the fatigue cracks initiate from the surfaces of samples. Due to the propagation and connection of the micro-cracks, macro-cracks form and fracture occurs eventually. 相似文献
14.
采用圆形横截面光滑试样,通过轴向不同应变幅控制的低周疲劳试验,研究了10CrNiMo高强钢的低周疲劳特性,包括循环应力-应变行为、应变-寿命特点、循环应力响应及其力学滞后现象,给出了相应的疲劳参数、循环软硬化特性及应变滞后规律.对裂纹扩展方向及试样疲劳断口的观察表明:裂纹扩展面与轴向力呈现多角度关系,裂纹萌生于试样表面,沿断口周边分布,且具有多源性;疲劳裂纹主要以锐化——钝化机制扩展. 相似文献
15.
16.
�������⺣������������������ 《钢铁研究学报》2015,27(11):48-53
The low cycle fatigue behaviors of Fe- Mn- C TWIP steels with different Ce contents were studied. The research was done with a total strain amplitude of ??0. 8% during cyclic loading. Microstructure evolutions of TWIP steels after fatigue fracture were observed by SEM and TEM. The experimental results indicate that TWIP steels with Ce and without Ce have the same characteristics of cyclic hardening, cyclic saturating, cyclic softening and final failure. The density of inclusions in the TWIP steel is increased by the addition of rare earth element Ce, which results in the absorption capability of fatigue energy of the TWIP steel is reduced. Therefore, Ce plays a negative role in deformation fatigue of TWIP steel. 相似文献
17.
18.
摘要:采用质量分数为5%的NaCl溶液在盐雾腐蚀箱进行30~90d加速腐蚀试验,研究了盐雾腐蚀对HRB400E钢筋低周疲劳行为和拉伸性能的影响。然后采用轴向位移控制模拟地震载荷对腐蚀钢筋开展了低周疲劳和拉伸试验,获得循环响应特征曲线和应变 寿命曲线。结合SEM断口形貌观察,分析钢筋的低周疲劳断裂机制。结果表明:盐雾腐蚀对钢筋的质量和尺寸有明显影响,钢筋表面产生腐蚀坑;钢筋的力学性能随腐蚀时间增加而降低,腐蚀90d的断裂伸长率下降率达461%,屈服强度在腐蚀30d以后可能就不再满足标准要求;腐蚀明显削弱了钢筋的抗循环载荷性能,导致低周疲劳寿命下降;腐蚀会减小钢筋的裂纹扩展区面积并加速裂纹扩展。 相似文献