电站风机叶轮用高强钢DL-700的焊接工艺研究

发布时间：2018-06-17 09:02

本文选题：火电厂 + 电站风机　；参考：《西南交通大学》2015年硕士论文

【摘要】：电力工业是一个国家的经济命脉,在国民经济和人民生活中占有极重要的地位。电站风机是火电厂不可或缺的重要设备,高强钢DL-700在高转速风机叶轮中的应用越来越广,对其进行相关焊接工艺研究具有较大的实用意义。本论文以DL-700钢为主要研究对象,首先对同类钢材的焊接性进行了详细分析，，然后对DL-700钢母材的基本力学性能进行了试验和分析,在此基础上研究了不同t8/5对焊接接头的性能影响，并以此为依据进行了与生产相关的焊接工艺评定。针对电站风机的磨损特点,从安全运行的角度出发,选用了2种典型耐磨焊材和2种过渡焊材,拟定了阻止耐磨层裂纹扩展至母材的相关试验。试验结果表明：DL-700钢板在不同的轧制方向上表现出基本无差异的抗拉强度、屈服强度和延伸率。DL-700钢焊接接头的力学性能受t8/5的变化影响很大,通过对试验数据的分析,得出t8/5的合理范围为7.1s～25.2s,与德国蒂森克虏伯(Thyssenkrupp)公司和标准SEW-088提出的推荐冷却时间t8/5较为吻合。DL-700钢同、异种钢的焊接工艺评定覆盖了DL-700钢生产中使用的所有焊接方法、焊接材料、焊接位置、工件厚度和可能焊接的异种钢,除选用的低组配焊材焊接的试板外,其余焊接工艺评定结果为合格,可在实际生产中进行运用。DL-700钢的耐磨处理可采用堆焊耐磨焊材的方式进行,无论堆焊后是否产生裂纹,均可在过渡层的作用下阻止裂纹的扩展,过渡焊材的选用对电站风机的安全运行有重要意义。最后,根据近年来采用DL-700钢制造电站风机叶轮的实践经验，对DL-700钢的焊接技术进行了总结。
[Abstract]:Electric power industry is the economic lifeline of a country and plays an important role in the national economy and people's life. The fan of power station is an indispensable and important equipment in thermal power plant. The application of high strength steel DL-700 in the impeller of high speed fan is more and more extensive. It is of great practical significance to study the related welding technology of DL-700. In this paper, DL-700 steel is taken as the main research object. Firstly, the weldability of the same steel is analyzed in detail, and then the basic mechanical properties of DL-700 steel base metal are tested and analyzed. On this basis, the effects of different t8 / 5 on the properties of welded joints were studied, and the welding process related to production was evaluated. According to the wear characteristics of power station fan, two kinds of typical wear-resistant welding materials and two kinds of transitional welding materials are selected from the point of view of safe operation, and the related tests to prevent the crack of wear-resistant layer from spreading to the base metal are made. The test results show that there is no difference in tensile strength between different rolling directions. The mechanical properties of welded joints of steel. DL-700 steel are greatly affected by the change of t 8 / 5. Through the analysis of test data, It is concluded that the reasonable range of t8 / 5 is 7.1 s-1 / 25.2s, which is consistent with the recommended cooling time t8 / 5 proposed by Thyssenkruppp (Thyssenkruppp) and the standard SEW-088. The welding process evaluation of dissimilar steel covers all the welding methods used in the production of DL-700 steel. Welding materials, welding positions, workpiece thickness and dissimilar steels that may be welded, in addition to the test plates for welding of selected low component welding materials, the other welding process evaluation results are qualified, The wear resistance treatment of .DL-700 steel can be carried out by surfacing wear-resistant welding material in actual production. Whether or not cracks are produced after surfacing welding, the crack propagation can be prevented under the action of transition layer. The selection of transitional welding materials is of great significance to the safe operation of power station fans. Finally, the welding technology of DL-700 steel is summarized according to the practical experience of using DL-700 steel to manufacture fan impeller in power station in recent years.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG457.11

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