316不锈钢长时总体一次薄膜应力强度许用值预测方法研究

材料的总体一次薄膜应力强度许用值(S_mt)是高温反应堆设备结构设计力学分析的重要判定依据,但美国机械工程师协会(ASME)的规范和法国《快堆核岛机械设备设计和建造规范》(RCC-MR)给出的最长30万小时的S_mt不能满足长寿期反应堆的设计要求。本文基于ASME规范给出的30万小时许用应力、预计最小断裂应力及断裂应力系数等材料蠕变性能数据,采用Larson-Miller外推模型成功获得了50万小时长寿期的316不锈钢母材和焊缝的长时蠕变性能,可满足长寿期反应堆的设计要求。     

Effect of Solute Titanium on Void Swelling in 316 Stainless Steel

To investigate the solute Ti effect on void swelling in stainless steels, the well-annealed 316 stainless steels modified with various amounts of Ti were electron-irradiated in a high voltage electron microscope (HVEM). It was found that the swelling decreased dramatically with increasing Ti content up to 0.25w/0. This strong dependence of swelling on Ti content arises mainly from the changes in void number density, although the void growth rate also decreases with increase in Ti content. The dependence of the void number density on Ti content is interpreted in terms of the vacancy trapping effect of Ti, which decreases the steady state free vacancy concentration and results in the effective suppression of the void nucleation rate.     

核电用316LN不锈钢的热机械疲劳性能研究

采用热机械疲劳试验方法研究316LN不锈钢的同相热机械疲劳行为,获得材料的疲劳数据。试验结果表明:316LN不锈钢的热机械疲劳行为是一个先强化后软化的过程;滞回曲线呈梭形,形状"饱满",具有良好的塑性变形能力,且随着温度范围增大,变形能力增强;在相同条件下,温度范围增大,材料的疲劳特征表现更为明显;在波动管运行条件下(温度≤320℃),应变对材料的疲劳寿命影响占主要作用;材料在120~320℃和120~230℃条件下的热机械疲劳寿命均大于350℃恒温低周疲劳寿命,说明采用传统的高温低周疲劳试验结果来评价波动管材料的热机械疲劳寿命过于保守。     

不锈钢316L单轴棘轮行为及其影响因素的研究

对不锈钢３１６Ｌ材料进行了多种平均应力以及多种应力幅值下的单轴循环加载棘轮效应试验,分析研究了平均应力大小及其历史对其棘轮效应的影响,以及应力值大小及其历史对其棘轮效应的影响,揭示了不锈钢３１６Ｌ的单轴棘轮效应演化的特征及导致这些特征的原因,得到一些有意义的结果,对建立能较为精确地估计结构的循环累积变形的本构模型具有一定的参考作用。     

Irradiation Creep-Swelling Interaction in Modified 316 Stainless Steel up to 200 dpa

The irradiation creep-swelling interaction parameters were pecisely derived for MONJU fuel pin cladding PNC316 by irradiation tests of pressurized tubes in FFTF. It was found out that a creep-swelling coupling coefficient decreased and asymptotically approached a constant value as the swelling progresses, although it was widely believed that the irradiation creep rate could be proportional to the swelling rate. This non-proportionality in the irradiation creep-swelling interaction was investigated by means of the rate theory analyses under sequential climb-controlled glide process of dislocation due to absorption of interstitial atoms. It was clarified through a constructed robust model that the presence of a precipitate sink should upset the proportionality of the net interstitial flux into dislocations to the net vacancy flux into the voids. In addition, irradiation creep parameters derived by material irradiation was demonstrated to be applicable for reasonably predicting the irradiation creep deformation in the fuel pins.     

冷变形316不锈钢在高温水中的应力腐蚀开裂行为

对不同冷变形量的核级316和316L不锈钢在高温水中的应力腐蚀开裂(SCC)行为进行了研究。通过试验,对溶解氧、氯离子和温度对裂纹扩展速率的影响进行了深入探讨和分析。试验结果显示,溶解氧和氯离子能明显加快材料的应力腐蚀开裂速率。当水化学条件一致时,325℃时的裂纹扩展速率较288℃时的裂纹扩展速率高。     

Mobilization of 316 Stainless Steel from 500 to 800°C in Steam

This paper presents the results of steam exposure tests of 316 stainless steel in the Fusion Aerosol Source Test (FAST) facility. The tests were performed at temperatures of 500,600,700, and 800°C. These tests were conducted to measure the mobilized material resulting from the steam exposure conditions at each temperature. A steam volume flow rate of 21–27 standard liters per minute was maintained in the test sections for a duration of 5 hours. These conditions simulate postulated accident conditions in the International Thermonuclear Experimental Reactor (ITER) relevant scenarios. These data will be used in safety assessments for ITER. We compared the data obtained in these tests with data from the Volatilization of Activation Product Oxides Reactor (VAPOR) facility at 800°C. The data obtained in the tests show the following: (1) There is a progressive increase of measured mass flux for Fe, Mo, Mn, Zn, and Cr with test temperature between 500°C and 800°C. (2) Mass flux measurements from FAST and VAPOR agree within a factor of three for elements with volatile oxide or hydroxide species such as Cr and Mo. (3) Mass fluxes of elements associated with oxide spalling in VAPOR, mainly Fe and Mn, were up to a factor of 90 lower in the FAST test than in the VAPOR test at 800°C. (4) Detection limits in FAST were lower than those measured in VAPOR due to the larger surface area of the source in FAST tests.     

Void Swelling of Solution-Annealed Type 316 Stainless Steel under Long Time Proton Irradiation

Solution-annealed type 316 stainless steel was irradiated by 150 keV proton to a dose of about 6 dpa at the irradiation temperature ranging 450–700°C. To examine the effect of aging during irradiation, the present proton irradiation was carried out for about 25 h at a low dose rate of 7×10–^?5dpa/s. The specimens without He preinjection showed much smaller void swelling than those preinjected with He to the content of 10 at.ppm. Similarly to the case of neutron irradiations, the void swelling in the He preinjected specimens showed the temperature dependence with double peaks, and the peak swelling temperatures were about 550 and 650°C. In these specimens with He preinjection. void number density decreased and average void diameter increased with the increase of irradiation temperature in the range of 450–600°C, but these trends were reversed between 600 and 650°C. The volume of the grain boudary M₂₃C6 precipitates increased with the increase of irradiation temperature from 600 to 700°C, and it was concluded that the decrease of soluble carbon due to the precipitation of M₂₃C6 caused the second swelling peak at 650°C.     

316 L不锈钢与氘氚气体长期作用后的显微组织研究

将长期与氘氚气体作用后的316L不锈钢容器不断充入氩气介质,直至容器破裂.用扫描电镜和透射电镜对其显微组织进行观察分析.结果表明破裂断口呈韧致断裂的韧窝形态,通过TEM观察到马氏体组织.通过分析认为,高应变诱发了奥氏体组织中马氏体转变,而氘、氚的存在进一步促进了奥氏体组织中的ε马氏体转变,从而降低了奥氏体不锈钢的层错能,导致其抗氢脆能力下降.     

10CrMo910和316不锈钢的时间相关失效评定曲线

对10CrMo910和316不锈钢进行了总计约1万小时的蠕变拉伸试验、得到了材料的等时应力应变曲线和时间相关失效评定曲线,并给出了长时蠕变情况下的时间相关失效评定曲线方程。