304L不锈钢代替321不锈钢的可行性研究

为了优选反应堆材料,本文对0Cr18Ni10Ti(321)和00cr19Ni10(304L)不锈钢的冶金性能、物理性能、力学性能、腐蚀性能、焊接性能、加工性能进行了对比分析.分析结果表明:304L不锈钢除了拉伸和蠕变强度比321不锈钢低一点外,其余性能在反应堆运行工况下比321不锈钢好.在反应堆中304L不锈钢可以替代的321不锈钢.     

管子与管板内孔焊试验

本文扼要介绍研制的小口径管子与管板内孔焊焊枪和1Cr18Ni9Ti ψ13×1.25毫米管子与管板对接内孔焊焊接工艺的一些特点,以及较佳的内孔焊规范参数和接头型式;并简要介绍00Cr25Ni25Si2V2Nb、00Cr18Ni5Mo2Si2Nb ψ3×1.25毫米管子与1Cr18Ni9Ti 管板接头内孔焊焊接工艺及消除裂缝的措施,以及较佳的内孔焊焊接参数;比较了1Cr18Ni9Ti、00 Cr25Ni25Si2V2Nb 和00Cr18Ni5Mo2Si2Nb 三种管材的内孔焊质量,评价了三种管材焊接性能的优劣。     

304NG不锈钢均匀腐蚀性能研究

用MARS循环腐蚀回路对304NG不锈钢进行了1500h的循环水腐蚀考验,对均匀腐蚀速率进行了定量评估。试验结果表明:在模拟核反应堆一回路循环水条件下,304NG控氮不锈钢板材、锻件的均匀腐蚀速率为1.40mg/(dm2ˇ30d)和1.91mg/dm2(dm2ˇ30d),0Cr18Ni10Ti不锈钢板材、锻件的均匀腐蚀速率为4.44mg/(dm2ˇ30d)和4.65mg/(dm2ˇ30d),304NG控氮不锈钢的均匀腐蚀速率低于0Cr18Ni10Ti不锈钢。     

不锈钢组件辐照装置环焊工艺研究

针对304不锈钢包壳管及端塞的焊接工艺开发,采用ABAQUS有限元软件,对不同焊接工艺参数下包壳管与端塞的温度场进行了数值模拟分析,初步确定了焊接工艺参数,后期通过少量的试验,制定了辐照装置的焊接工艺规范。     

不锈钢件钎焊前镀镍工艺

一、前言电子直线加速器的各波导管(TU_1),均用不锈钢(1Cr18Ni9Ti)法兰(见图1)进行连接。而波导管与法兰之间则是用Ag-Cu共晶钎料在氢炉中焊接成一体的。根据钎焊的工艺要求,不锈钢法兰在焊前必须先镀一层镍,     

反应堆冷却剂主管道316LN新型管材替代321管材的可行性研究

采用对比分析法对国产新研制的控氮00Cr17Ni12Mo2(ANSI316LN)与0Cr18Ni10Ti(ANSI321)不锈钢管材的化学成份、力学性能、耐腐蚀性能等进行研究。研究表明,316LN新型管材综合性能在反应堆一回路系统运行工况下优于321管材,完全可以实现对321管材的替代。     

GH-169镍基合金、0Cr18Ni9Ti奥氏体不锈钢钎焊缝中相的鉴定

本文介绍了用分析电镜,对 GH-169镍基合金、0Cr18Ni9Ti 奥氏体不锈钢为母材的钎焊缝进行的研究。鉴定了用不同的母材和不同的钎料时,焊缝中所形成的相.     

Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺研究

采用BNi-5钎料,对Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺进行试验研究,对试验钎焊的接头进行了密封性能检验、抗热冲击性能试验、接头界面区微观分析以及钎缝拉伸强度试验.通过分析试验结果,确定了Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺规范参数.     

氢在TiC膜-1Cr18Ni9Ti不锈钢中的渗透行为

用离子束辅助沉积法在1Cr18Ni9Ti不锈钢表面制备了TiC膜,并对其进行了XPS,SEM及SIMS等微观结构分析,测定了氢在有TiC膜的1Cr18Ni9Ti不锈钢中的渗透率.研究结果表明,制备的TiC膜致密性好且均匀,厚度约为15 μm; TiC膜中有大量的CH-4负离子存在,在473～773 K范围内,氢的渗透率降低了4～5个数量级.     

冲击载荷作用下管道焊缝裂纹的动态断裂韧性计算

冲击载荷作用下管道焊缝裂纹的起始扩展研究对管道系统的安全性和寿命预测具有重要意义.文章以实验为基础,采用大型有限元软件ABAQUS对动态断裂实验进行有限元数值模拟,研究三维动态断裂力学的有限元建模技术及其有限元网格生成技术.通过计算,得到了0Cr18Ni10Ti管道焊缝材料在冲击载荷作用下的动态起裂韧性.     

控制棒环焊缝的脉冲钨极氩弧焊

介绍了巴基斯垣恰希玛核电站（ＰＣ）控制棒环焊所采用的脉冲钨极氩弧焊（以下简称脉冲ＴＩＧ焊）的工艺特点以及对０Ｃｒ１８Ｎｉ１１Ｔｉ冷作奥氏体不锈钢材料的适用性，分析总结了焊接缺陷产生的原因和采取的措施。     

1Cr18Ni9Ti不锈钢低周疲劳随动硬化实验研究

为了研究单调加载对1Cr18Ni9Ti不锈钢材料后继循环塑性硬化和流动特性的影响,对该材料进行了带平均应变的低周疲劳实验研究.对不同应变幅值的对称应变及非对称的应变循环进行了屈服面半径和背应力演化分析,揭示了材料的随动硬化和各向同性硬化演化对应变幅值和平均应变的依赖性.实验结果为建立循环加载和单调加载耦合的复杂加载条件下的本构模型提供了实验基础.     

Non-equilibrium intragrain concentration redistribution of the alloying elements in austenitic steels under irradiation

Radiation-induced and thermally activated decomposition of austenitic 16Cr15Ni3Mo1Ti, 32Ni, 34Ni steels at high temperature (500–650°C) were examined. High doses (up to 10–200 dpa ) in 16Cr15Ni3Mo1Ti stainless steel with 1.5 MeV Kr ions and 450 keV Fe ions at 550–650°C lead to the appearance of relatively large regions (up to 200–400 nm) of concentration-oscillations with ‘mosaic’ dark–white diffraction contrast in TEM images. The radiation-induced redistribution of alloying elements takes place thanks to inverse Kirkendall effect and, in particular, removal of Cr to cell volume from boundaries of coarse cellular structure. The competing formation of ultrafine subgrains and grains 10–50 nm in size structure in Ti-free steel (16Cr15Ni3Mo) impedes the development of large ingrain segregations. The Mössbauer investigations showed that the 32Ni and 34Ni steels with purposefully produced concentration-oscillations were fully homogenised in that high-temperature region. This fact indicated the absence of the thermal decomposition dome in the Fe–Ni equilibrium diagram.     

几种去污工艺对压水堆一回路模拟氧化物的溶解及腐蚀研究

为了获得较高的去污系数以及对被去污件较低的腐蚀程度,需要选择相对适宜的去污工艺。本研究工作选取不锈钢1Cr18Ni9Ti和Inconel 690合金,通过高压釜制备模拟氧化物试片,采用不同去污工艺,进行试片表面模拟氧化物的溶解及腐蚀试验。结果表明:酸性高锰酸钾溶液对于压水堆模拟氧化物的预氧化处理效果好于碱性高锰酸钾溶液;两种模拟氧化物试片经过四种不同去污工艺处理后,通过对去污后试片的宏观及微观观察,几种去污工艺均未对试片结构造成破坏;NP-CITROX是一种比较理想的去污工艺。     

321不锈钢在低酸度硝酸铀酰溶液中的腐蚀特性

用称量法和电化学法研究了321不锈钢在不同浓度和pH值的硝酸铀酰溶液中的高温均匀腐蚀和电化学府蚀行为。均匀腐蚀试验结果表明．在选定的腐蚀条件下，321不锈钢样品在960h内，其表面光洁度无明显变化．腐蚀速率小于0．04mg/m^2.h，在低酸度的硝酸铀酰溶液中耐蚀。用腐蚀电入学法研究了321不锈钢在有溶解氧的硝酸铀酰溶液中的腐蚀电化学特性，测量了电极的腐蚀电位、腐蚀电流密度。经AES分析表明，电化学腐蚀后的样品在腐蚀膜中有一定量的铀．深度剖析含铀腐蚀膜的厚度为10—15nm。     

熔融池相变传热特性的大涡模拟数值研究

研究反应堆熔融池内部的流动与传热特性对保证熔融物堆内滞留具有重要意义。本文基于开源软件OpenFOAM平台,结合大涡模拟湍流方法和熔融池相变过程建立熔融池传热模型,针对典型熔融池传热实验LIVE工况开展数值计算,得到了熔融池内速度场和温度场以及下封头内壁面硬壳厚度和热流密度分布情况。结果表明,熔融池内速度、温度和热流密度随高度或径向角度的增大而增大;硬壳厚度随径向角度的增大而减小;下封头壁面上的热负荷在顶部聚集。传热参数计算结果与实验数据整体符合较好,可以有效反映出熔融池内自然对流与相变过程,验证了计算模型的可靠性,可为进一步研究熔融池相变传热特性提供参考。      

Statistical model for the random cyclic strain–life relations of 1Cr18Ni9Ti pipe-weld metal under temperature of 240°C

Modeling of random cyclic strain–life (CSL) relations of engineering material should be a basis of strain-based fatigue reliability analysis. A statistical model for the relations of a nuclear engineering material, 1Cr18Ni9Ti stainless steel pipe-weld metal under temperature of 240°C, is presented. In the model, a verified distribution, i.e. lognormal distribution, is used as an appropriate assumed distribution of the material fatigue life data. Based on the Coffin–Manson law, the relations are modeled by mean value- and standard deviation-cyclic curves of the logarithm of fatigue life. Then, fatigue analysis at an arbitrarily given probability can be made conveniently according to the normal distribution function. An approach for estimating the curves and their confidence bounds is developed by a linear regression technique. Different from the existent reliability analysis methods that considered the material constants in the law as independently random variables, present work treats them as dependently random variables from the fit of test data. Availability of the model has been indicated by an analysis of the material test data.     

Predicting welding residual stresses in a dissimilar metal girth welded pipe using 3D finite element model with a simplified heat source

Dissimilar metal welds are commonly used in nuclear power plants to connect low alloy steel components and austenitic stainless steel piping systems. The integrity assessment and life estimation for such welded structures require consideration of residual stresses induced by manufacturing processes. Because the fabrication process of dissimilar metal weld joints is considerably complex, it is very difficult to accurately predict residual stresses. In this study, both numerical simulation technology and experimental method were used to investigate welding residual stress distribution in a dissimilar metal pipe joint with a medium diameter, which were performed by a multi-pass welding process. Firstly, an experimental mock-up was fabricated to measure the residual stress distributions on the inside and the outside surfaces. Then, a time-effective 3-D finite element model was developed to simulate welding residual stresses through using a simplified moving heat source. The simplified heat source method could complete the thermo-mechanical analysis in an acceptable time, and the simulation results generally matched the measured data near the weld zone. Through comparing the simulation results and the experimental measurements, we can infer that besides the multi-pass welding process other key manufacturing processes such as cladding, buttering and heat treatment should also be taken into account to accurately predict residual stresses in the whole range of the dissimilar metal pipe.     

1Cr_(18)Nl_9Ti钢的低周疲劳特性研究

通过对:Cr_(18)Ni_9Ti钢的低周疲劳循环试验,进行了试验结果的回归分析研究,给出了轴向总应变与循环寿命,以及总应变与循环至发生工程裂纹寿命的关系。