应变强化奥氏体不锈钢压力容器研究与设计

发布时间：2018-06-14 00:08

本文选题：国产奥氏体不锈钢 + 应变强化　；参考：《华南理工大学》2011年硕士论文

【摘要】：奥氏体不锈钢在压力容器行业应用日益广泛,同时奥氏体不锈钢又具有屈强比低,价格昂贵,塑性,韧性良好的特征。与常规设计方法相比,应用应变强化设计的奥氏体不锈钢压力容器,可以减小容器设计壁厚,减轻容器重量,降低重容比,减少容器制造与运输过程中的能耗,实现容器的绿色制造,达到低碳经济的目标。本文在参阅大量国内外文献的基础上,结合企业生产实际,通过对国产奥氏体不锈钢06Cr19Ni10力学性能测试,研究应变强化对材料力学性能的影响;结合材料试验结果并通过有限元分析了筒体,球壳及实际的容器模型在强化压力下的应力应变状况;对比分析了国外的相关标准,并结合材料的试验结果及生产实际研究了应变强化奥氏体不锈钢压力容器的设计和制造工艺流程。本文的主要研究内容和结论如下: (1)国产奥氏体不锈钢06Cr19Ni10力学性能测试。测试结果表明,不同批次的钢板应变强化前后力学性能相差较大;经应变控制的预拉伸变形后,材料屈服极限可以达到预期值;随着应变程度的增加,材料的屈服极限不断增加,塑性指标包括断后延伸率及断面收缩率不断下降;保压使材料应变量增加,并使屈服极限稍有增加,塑性指标略有下降;预应变量在10%以内时,强化后材料的断后延伸率仍能满足标准要求;在试验的应变强化范围内,强化后所有材料的常温和低温韧性都能满足标准要求; (2)强化压力下压力容器应力应变分析。容器在强化应力下的周向应变可以采用第四强度理论等效应力与单轴拉伸的应力状态对应,并根据材料的真实应力应变曲线中对应的应变来进行换算;在Mises应力相等的情况下柱体的周向应变为单向拉伸下应变的0.87倍,球壳的周向应变为单轴拉伸下应变的0.5倍;由于在同样的强化应力下,球壳的等效应力大于筒体的等效应力,因此球壳发生更多的应变;分析了开孔容器在强化压力下的应力应变状态,椭圆形封头存在强化不足的情况,不连续区存在一定的应力集中但影响范围较小,容器远离结构不连续的区域可以达到预期强化效果; (3)分析了现有国外应变强化压力容器标准的异同,研究了应变强化压力容器的设计方法,并将之应用于容器的设计实例;与常规的设计相比,采用应变强化技术可以有效降低容器的壁厚;同时结合奥氏体不锈钢压力容器的实际生产情况,研究了应变强化奥氏体不锈钢压力容器制造工艺流程。
[Abstract]:Austenitic stainless steel is widely used in pressure vessel industry, and austenitic stainless steel has the characteristics of low yield ratio, high price, good ductility and toughness. Compared with the conventional design method, the design of austenitic stainless steel pressure vessel by strain strengthening can reduce the design wall thickness, reduce the weight of the vessel, reduce the weight ratio, and reduce the energy consumption during the manufacture and transportation of the vessel. To achieve the green container manufacturing, to achieve the goal of low-carbon economy. In this paper, the effect of strain strengthening on mechanical properties of domestic austenitic stainless steel 06Cr19Ni10 has been studied by referring to a large number of domestic and international literatures and combining with the production practice of the enterprise, through testing the mechanical properties of domestic austenitic stainless steel 06Cr19Ni10. Combined with the results of material test and finite element analysis, the stress and strain conditions of cylinder, spherical shell and actual vessel model under strengthened pressure are analyzed, and the relative standards of foreign countries are compared and analyzed. The design and manufacturing process of strain strengthened austenitic stainless steel pressure vessel were studied. The main contents and conclusions of this paper are as follows: 1) the mechanical properties of domestic austenitic stainless steel 06Cr19Ni10 are tested. The test results show that the mechanical properties of different batches of steel plates are different before and after strain strengthening, the yield limit of the materials can reach the expected value after strain controlled pretensile deformation, and with the increase of strain degree, The yield limit of the material is increasing, the plastic index including the elongation after fracture and the shrinkage of the section are decreasing; the strain of the material is increased by keeping pressure, and the yield limit is slightly increased, and the plastic index is slightly decreased; when the prestrain is less than 10%, In the range of strain strengthening, the toughness of all the strengthened materials at room temperature and low temperature can meet the standard requirements; and the stress-strain analysis of pressure vessels under strengthened pressure can be achieved. The circumferential strain of the vessel under the strengthened stress can be converted according to the corresponding strain in the true stress-strain curve of the material by using the fourth strength theory and the stress state of uniaxial tension. When Mises stress is equal, the circumferential strain of cylinder is 0.87 times that of uniaxial tension, and the circumferential strain of spherical shell is 0.5 times that of uniaxial tension. Therefore, more strain occurs in the spherical shell, the stress and strain state of the perforated vessel under the strengthened pressure is analyzed, the elliptical head has the condition of insufficient strengthening, the stress concentration in the discontinuous region is certain but the influence range is relatively small. The expected strengthening effect can be achieved when the vessel is far away from the region with discontinuous structure. (3) the similarities and differences of the existing foreign strain-strengthening pressure vessel standards are analyzed, and the design method of the strain-strengthened pressure vessel is studied. Compared with the conventional design, the strain strengthening technique can effectively reduce the wall thickness of the vessel, and combine with the actual production of austenitic stainless steel pressure vessel. The manufacturing process of strain-strengthened austenitic stainless steel pressure vessel was studied.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH49

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