论文总字数：30420字

摘 要

当前，随着我国实体经济的逐步回暖，过程装备行业得到了迅速的发展，其中加氢反应器的应用也日益广泛。选用高强度的铬钼钢作为制造加氢反应器的材料逐渐成为现在的主流趋势。其中的2.25Cr1MoV材料具有较高的强度刚度、优良的耐高温性能、抵御氢腐蚀的性能、良好的可焊接性能，是制造在高温临氢恶劣环境中服役的加氢反应器的优良材料。2.25Cr1MoV钢在工况条件下可能出现母材及焊接部位的氢脆，回火脆化现象，使材料力学性能明显下降。为此研究2.25Cr1MoV钢在含裂纹结构的失效评定曲线显得至关重要。本文主要采用EPRI的积分工程计算法和R6-option3的缺陷评定法，以四种典型试样（CCP、CT、SECP、DECP）为研究对象，通过拉伸试验和数值计算分析，研究2.25Cr1MoV钢在氢脆条件下平面应力、应变条件状态的失效评定曲线，研究主要内容如下：

1. 通过对2.25Cr1MoV母材在脱脆及脱脆充氢状态下的拉伸试验，获得母材的应力-应变关系，对其进行拟合，得出Ramberg-Osgood本构关系和相应的本构关系参数。
2. 利用拉伸试验所得数据算出试样在两种状态下，三种裂纹尺寸（a/w=0.25、a/w=0.5、a/w=0.75）相应的极限载荷，并绘制出相应的不同裂纹尺寸对应的极限载荷图，分析比较其差异。
3. 计算出四种类型2.25Cr1MoV 试样，分别计算在脱脆、脱脆充氢、平面应力、平面应变以及不同裂纹尺寸条件下的积分值，并对比研究其变化规律。
4. 基于EPRI的积分工程计算法和R6的选择3方法，建立了四种典型试样在三种不同裂纹尺寸、平面应力、应变条件下的失效评定曲线图，并将其与R6通用失效曲线（选择1）进行对比。最后研究了材料在氢脆条件下失效评定曲线的变化规律。

关键词： 2.25Cr1MoV钢 氢脆 裂纹结构 积分 EPRI工程估算法 失效评定曲线

Abstract

At present, with the gradual recovery of China's real economy, the process equipment and control engineering industry has been increasingly developed, and the application of hydrogenation reactor is increasingly widespread.It is a main trend to choose high strength Cr-Mo steel as the material of hydrogenation reactor.Among them, 2.25Cr1MoV material has high strength and rigidity, excellent good temperature resistance, hydrogen corrosion resistance, and good weldability. It is an excellent material for manufacturing hydrogenation reactor in high temperature hydrogen environment.Hydrogen embrittlement and tempering embrittlement may occur in the base metal and weldment of 2.25Cr1MoV steel under working conditions, which makes the mechanical properties of the material significantly reduced.Therefore, it is of great necessity to study the failure assessment curve of base metal with crack structure.In this paper, EPRI-J integral engineering calculation method and R6-option3 defect evaluation methods are used. Four typical specimens (CCP, CT, SECP, DECP) are taken as research objects. Through tensile test and numerical calculation analysis, the failure assessment curves of 2.25Cr1MoV steel base metal based on plane stress and plane strain are studied. The main research contents are as follows:

(1) Through the tensile test of 2.25Cr1MoV base metal in the state of de-embrittlement and hydrogen charging, the stress-strain curve of the base metal was obtained, and the Ramberg-Osgood relationship and corresponding parameters were obtained.

(2) According to the data of tensile test, the limit loads of three crack sizes (a / w = 0.25, a / w = 0.5, a / w = 0.75) are calculated under two states, and the corresponding limit load curves of different crack sizes were drawn , and the differences, were analyzed and compared.

(3)J-integral of four types of 2.25Cr1MoV specimens were calculated . The integral values were obtained under the conditions of de-embrittlement, hydrogen charging, plane stress, plane strain and different crack sizes.After that, the Origin software was taken to draw the corresponding curve, and the changes of different conditions were compared.

(4) Based on EPRI-J integral engineering calculation method and R6 Option 3 method, the failure assessment curves of four typical specimens with three different crack sizes under plane stress and plane strain conditions were established.It was compared with R6 general failure curve (option 1) to verify the accuracy of FAC diagram when the load ratio did not exceed a certain value. Finally the changes rule of failure assessment curves under the condition of hydrogen embrittlement were studied.

Key words : 2.25Cr1MoV steel; Hydrogen embrittlement; Crack structure; J-integral; EPRI engineering calculation method; Failure assessment curve

目 录

摘 要 I

Abstract II

目 录 IV

第1章 绪 论 1

1.1引言 1

1.2氢脆相关理论 2

1.2.1氢脆来源 2

1.2.2氢脆机理 2

1.3极限载荷理论 3

1.3.1极限载荷确定准则 3

1.3.2极限载荷分析研究现状 3

1.4积分理论 4

1.5失效评定图方法 4

1.5.1失效评定规范标准 5

1.5.2常用失效评定方法 6

1.5.3缺陷评定现状 8

1.6本文研究的主要内容及技术要求 9

1.6.1主要内容 9

1.6.2 关键技术 9

第2章 2.25CR1MOV母材充氢下力学性能测试及本构关系回归 10

2.1引言 10

2.2电化学充氢装置 10

2.2.1充氢试验原理 10

2.2.2充氢试验 11

2.3 2.25CR1MOV母材拉伸性能实验 12

2.3.1拉伸实验 12

2.4本章小结 15

第3章 2.25CR1MOV母材充氢状态下的极限载荷分布 16

3.1引言 16

3.2 2.25CR1MOV钢紧凑拉伸试样(CT)的极限载荷分析 16

3.3 2.25CR1MOV钢中心裂纹版试样（CCP）的极限载荷分析 17

3.4 2.25CR1MOV钢双边裂纹版试样（DECP）的极限载荷分析 19

3.5 2.25CR1MOV钢受拉伸单板裂纹板（SECP）的极限载荷分析 20

3.6本章小结 21

第4章2.25CR1MOV母材充氢条件下积分研究 23

4.1引言 23

4.2四种典型试样的积分计算法 23

4.2.1 2.25Cr-MoV钢紧凑拉伸试样弹-塑性解 23

4.2.2 2.25Cr-MoV钢中心裂纹板弹-塑性解 24

4.2.3 2.25Cr-MoV钢双边裂纹板试样弹-塑性解 25

4.2.4 2.25Cr1MoV钢单边裂纹板试样弹-塑性解 27

4.3紧凑拉伸试样CT裂纹尺寸对母材积分的影响 28

4.4中心裂纹试样CCP裂纹尺寸对母材积分的影响 29

4.5双边裂纹板试样DECP裂纹尺寸对母材积分的影响 30

4.6单边裂纹板试样SECP裂纹尺寸对母材积分的影响 31

4.7本章小结 32

第5章2.25CR1MOV母材充氢状态下失效评定图研究 34

5.1引言 34

5.2 2.25CR1MOV母材建立方法 34

5.3不同类型试样裂纹尺寸（a/w）对失效评定曲线的影响 35

5.3.1中间裂纹板CCP试样a/w与失效评定曲线的关系 35

5.3.2紧凑拉伸CT试样a/w与失效评定曲线的关系 37

请支付后下载全文，论文总字数：30420字