共查询到17条相似文献,搜索用时 921 毫秒
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室温应变强化技术可大幅提高奥氏体不锈钢的屈服强度,显著减薄容器壁厚,已广泛应用于奥氏体不锈钢深冷容器制造。采用金相显微镜、X射线衍射仪(XRD)、透射电子显微镜(TEM)和摆锤式冲击试验机研究应变强化对S30408奥氏体不锈钢低温冲击性能的影响。结果表明:材料在应变强化过程中发生应变诱发相变,相变产物为α'和ε马氏体,深冷低温对应变强化材料的相组成和含量影响不大。随着应变量的增加和温度的降低,材料冲击吸收能量KV2降低,其中裂纹扩展能EP基本不变,裂纹形成能Ei显示与总冲击吸收能量相似的变化趋势。当温度低于77 K,冲击吸收能量下降趋于平缓,呈现出"平台"现象,且应变强化对材料低温冲击性能的影响要大于温度对其的影响。即使经过15%应变量,材料仍表现出较好的低温冲击韧性。 相似文献
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由于较好的低温性能,奥氏体不锈钢被广泛应用于LNG低温储罐,而奥氏体不锈钢的应变强化技术能提高材料的屈服强度实现容器的轻量化设计。在工程上,奥氏体不锈钢材料性能数据呈现一定的离散性,在压力容器制造和使用过程中,容器的尺寸和使用条件也是随机变量。利用可靠性设计中的一次二阶矩法和ANSYS软件中的Prob Design模块,可以得到了应变强化前后容器关键参数的随机分布,从而得到强化前后结构可靠度的变化,为奥氏体不锈钢应变强化容器的设计和制造提供支持。 相似文献
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《现代制造技术与装备》2016,(6)
奥氏体不锈钢材料本身具有良好的韧性,但它的屈服强度比较低,而应变强化技术能够显著提升奥氏体不锈钢材料的屈服强度,节约材料。奥氏体不锈钢压力容器的应变强化具有两种不同的模式:常温应变强化模式和低温应变强化模式。本文通过对应变强化基本原理的介绍,对奥氏体不锈钢压力容器的应变强化技术进行分析探讨。 相似文献
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对奥氏体不锈钢低温压力容器常规设计与应变强化设计进行比较,可知应变强化技术可大幅提高奥氏体不锈钢材料的许用应力,减薄简体壁厚,减轻容器重量。根据预应变拉伸试验确定国产S30408奥氏体不锈钢应变强化压力容器的应变上限值,并建立国产S30408奥氏体不锈钢材料的ASME和双线性这两种应力应变曲线,对两者进行比较后,以ASME应力应变曲线为计算依据,考虑抗拉强度的影响,确定了国产S30408奥氏体不锈钢材料制造应变强化低温容器时的许用应力及其对应的应变。 相似文献
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针对奥氏体不锈钢塑性和韧性优良但屈服强度低的问题,提出采用应变强化工艺来提高奥氏体不锈钢的屈服强度。研究了应变强化工艺中的两个关键工艺参数——应变量和应变速率对材料力学行为的影响。对应变量的研究结果表明,将奥氏体不锈钢的应变强化量控制在10%左右,材料的屈服强度可以得到显著提高。由此可大幅减薄压力容器的设计壁厚,实现压力容器的轻型化设计。与此同时,在10%左右的形变量下,因形变诱发的马氏体量很少,材料仍保持了较好的塑性和韧性,为压力容器的安全设计提供了保证。对应变速率的研究结果表明,在准静态条件下,奥氏体不锈钢材料力学性能指标对应变速率不敏感,但过小的应变速率会导致材料出现锯齿形屈服,产生Portevin-Le Chatelier(PLC)效应。 相似文献
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Most research to date concerning the cryogenic toughness of austenitic stainless steels has concentrated on the base metal and weld metal in weldments. The most severe problem faced on the conventional austenitic stainless steel is the thermal aging degradation such as sensitization and carbide induced embrittlement. In this paper, we investigate the cryogenic toughness degradation which can be occurred for austenitic stainless in welding. The test materials are austenitic stainless JN1, JJ1 and JK2 steels, which are materials recently developed for use in nuclear fusion apparatus at cryogenic temperature. The small punch (SP) test was conducted to detect similar isothermally aging condition with material degradation occurred in service welding. The single-specimen unloading compliance method was used to determine toughness degradation caused by thermal aging for austenitic stainless steels. In addition, we have investigated size effect on fracture toughness by using 20% side-grooved 0.5TCT specimens. 相似文献
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Mechanical and metallurgical properties of friction welded AISI 304 austenitic stainless steel 总被引:1,自引:1,他引:0
P. Sathiya S. Aravindan A. Noorul Haq 《The International Journal of Advanced Manufacturing Technology》2005,26(5-6):505-511
Owing to the superior properties, of stainless steel it is pertinent to make use of it in various automotive, aerospace, nuclear, chemical and cryogenic applications. It is observed that a wide range of dissimilar materials can be easily integrated by solid phase bonding techniques, such as friction welding and explosive bonding. This study mainly focuses on friction welding of AISI 304 austenitic stainless steel. The friction processed joints are evaluated for their integrity and quality aspects. Friction welding of austenitic stainless steel was carried out using a KUKA friction welding machine (Germany). As the friction time increased, the fully plastically deformed zone (region I) in the vicinity of the bond line becomes increased. In contrast, an increase in friction time will decrease the region (region II) where the grains are partly deformed and grown. Tensile test results indicated that, the joint strength is decreased with an increase of the friction time. The detailed fractographic observation confirmed that the rupture occurred mostly at the joint zone and partly through the base material. 相似文献
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P. Sathiya S. Aravindan A. Noorul Haq 《The International Journal of Advanced Manufacturing Technology》2005,26(5):505-511
Owing to the superior properties, of stainless steel it is pertinent to make use of it in various automotive, aerospace, nuclear, chemical and cryogenic applications. It is observed that a wide range of dissimilar materials can be easily integrated by solid phase bonding techniques, such as friction welding and explosive bonding. This study mainly focuses on friction welding of AISI 304 austenitic stainless steel. The friction processed joints are evaluated for their integrity and quality aspects. Friction welding of austenitic stainless steel was carried out using a KUKA friction welding machine (Germany). As the friction time increased, the fully plastically deformed zone (region I) in the vicinity of the bond line becomes increased. In contrast, an increase in friction time will decrease the region (region II) where the grains are partly deformed and grown. Tensile test results indicated that, the joint strength is decreased with an increase of the friction time. The detailed fractographic observation confirmed that the rupture occurred mostly at the joint zone and partly through the base material. 相似文献
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G. Madhusudan Reddy K. Srinivasa Rao 《The International Journal of Advanced Manufacturing Technology》2009,45(9-10):875-888
Microstructure and mechanical properties of similar and dissimilar welds of austenitic stainless steel (AISI 304), ferritic stainless steel (AISI 430), and duplex stainless steel (AISI 2205) have been studied. Welding processes electron beam welding and friction welding were used. Optical, scanning electron microscopy, and electron probe microscopy were carried out to study the microstructural changes. Residual stress, hardness, tensile strength, and impact toughness testing were conducted to study mechanical behavior. Dissimilar metal electron beam welds of austenitic–ferritic, ferritic–duplex, and austenitic–duplex stainless steel welds contained coarse grains, which are predominantly equiaxed on austenitic, duplex stainless steel side, and they are columnar on the ferritic stainless steel side. Diffusion of elements was significant in electron beam welding and insignificant in friction welds. Austenitic–ferritic stainless steel exhibited tensile residual stress on the ferritic stainless steel side adjacent to the interface, compressive stresses on the austenitic stainless steel side that matches with the delta ferrite microstructure observed in this region. High compressive stresses were noted on duplex stainless steel side interface compared to austenitic stainless side interface. The highest tensile strength was observed in duplex–austenitic stainless steel joints. The impact strength and notch tensile strength of electron beam weldments are higher than the friction weldments. All electron beam and friction welds showed toughness lower than parent metals. 相似文献