论文总字数：17137字

摘 要

泵是过程装备中的动设备，在热电和石油化工等领域被广泛的应用。泵作为热电和石油化工等工厂重要的的源动力和装备，对石油化工工业和社会经济的发展起着十分重要的作用。

某工厂有多台凝结水泵，使用该凝结水泵将凝汽器的凝结水排出凝结器。一台大型凝结水泵在使用过程中其电机主轴发生了断裂失效，为查明失效原因，通过金相显微组织、冲击性能、扫描电镜、显微硬度等方法对泵轴的力学性能和组织进行检验和分析。主要工作和结论如下：

（1）电机轴断口呈现典型的低应力脆性断口的形貌，电机轴断裂具有低应力高周疲劳断裂特征，裂纹源主要出现在电机轴的外边界和部分出现在电机轴内部，且具有多源性。

（2）断裂电机轴材料的金相显微组织是铁素体和珠光体组织，而不是均匀细小的回火索氏体。这结果表明电机轴的热处理是正火热处理，而未进行调质热处理。材料中存在微缺陷（夹杂、气孔或微裂纹），这些缺陷破坏了材料的连续性，会降低材料的综合机械性能，从而降低电机轴的抗疲劳裂纹扩展能力。

（4）该电机轴材料的拉伸性能和电机轴硬度符合标准的要求，但是冲击性能不符合标准的要求。

关键词：离心泵 泵轴 力学性能 试样

Fracture failure analysis of main shaft of centrifugal pump motor

ABSTRACT

Pumps are rotating equipment in process equipment and are widely used in thermoelectricity and petrochemical industries. As an important source of power and equipment for factories such as thermoelectric and petrochemical plants, pumps play an important role in the development of the petrochemical industry and social economy.

A factory has multiple condensate pumps, which are used to discharge the condensate from the condenser. A large-scale condensate pump suffered a fracture failure on the motor shaft during use. To identify the cause of the failure, the pump shaft was subjected to metallurgical microstructure, impact performance, scanning electron microscopy, and microhardness. Inspection and analysis of mechanical properties and organization. The main work and conclusions are as follows:

(1) The fracture of the motor shaft presents a typical low-stress brittle fracture. The fracture of the motor shaft has the characteristics of low stress and high-cycle fatigue fracture. The crack source mainly appears on the outer boundary and part of the motor shaft and appears inside the motor shaft. Source.

(2) The metallographic microstructure of the broken motor shaft material is ferrite and pearlite, not uniform and fine tempered sorbite. This result indicates that the heat treatment of the motor shaft is normalizing heat treatment, but no quenching and tempering heat treatment. There are micro defects (inclusions, pores or micro cracks) in the material. These defects destroy the continuity of the material and will reduce the overall mechanical properties of the material, thereby reducing the fatigue crack growth resistance of the motor shaft.

(3) The tensile properties of the motor shaft material and the motor shaft hardness meet the requirements of the standard, but the impact performance does not meet the requirements of the standard.

KEYWORDS:Centrifugal pump;Pump shaft;Mechanical property;sample

目录

摘 要 I

ABSTRACT II

第一章 绪论 1

1.1离心泵研究背景 1

1.2离心泵工作原理 1

1.3近年来国内外离心泵的研究现状 3

1.4 本课题研究的目的及意义 5

1.5 本课题的主要研究内容 6

第二章 离心泵电机主轴断口的形貌分析 8

2.1引言 8

2.2宏观断口形貌分析方法 8

2.3本章小结 8

第三章 电机主轴材料的金相组织和显微硬度试验 11

3.1引言 11

3.2金相组织试验 11

3.2.1试验方法 11

3.2.2试验结果及分析 13

3.3显微硬度试验   17

3.3.1显微硬度实验方法 18

3.3.2显微硬度试验结果 18

3.4本章小结 19

第四章 电机主轴材料的力学性能试验 21

4.1引言 21

4.2电机轴材料的拉伸性能分析 21

4.2.1试验方法 21

4.2.2实验结果及分析 22

4.3电机轴材料的冲击性能分析 23

4.3.1试验方法 23

4.3.2实验结果及分析 24

4.4本章小结 25

第五章 结论及经济评价 26

5.1结论 26

5.2经济评价 26

参考文献 28

致谢 30

第一章 绪论

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