提高2.25Cr—1Mo钢的力学性能的研究

主要从化学成分和热处理工艺入手,研究了影响2.25Cr—1Mo钢锻件重温强度和低温冲击韧性的主要因素。试验证明,采用合理的热处理工艺,可以使壁厚在410mm以下的2.25Cr—1Mo钢锻件满足目前国内外加氢反应器最苛刻的技术要求。     

2.25Cr—1Mo钢厚壁容器环缝横向裂纹的研究

用２．２５Ｃｒ－１Ｍｏ钢制造的加氢反应器,筒体环缝由于工艺原因,出现了垂直于焊缝方向的横向裂纹其特点是埋伏在焊缝表面下１５－２５ｍｍ,超声波探伤不易发现因此,危害性较大,本文阐述了产生横向裂纹的情况,并通过焊接接头试验,裂纹解剖 分析,对今后铬钼钢压力容器生产中如何克服和防止产生横向裂纹提出了一些建议。     

Cr5Mo耐热钢在锻热生产中的几个问题

SeveralProblemsintheForgingandHeatTreatmentProcessesofCr5MoHeatResistantSteelWangXianmin1引言Cr5Mo钢系珠光体型耐热钢。适用于制造石油蒸馏设备的管道及容器等。此外还广泛用来制作热交换器和过热蒸汽管道、燃油泵和阀门等零件。通常使用的温度在650℃以下。2Cr5Mo钢的     

20G和2.25Cr—1Mo钢氢蚀后的疲劳性能

对２０Ｇ和２．２５Ｃｒ－１Ｍｏ钢经不同程度氢蚀后的常规力学性能与疲劳裂纹扩展行为进行了对比研究。并对氢蚀组织变化与裂纹扩展路径进行了显微观察。结果表明，氢蚀使２０Ｇ钢的疲劳裂纹扩展速率明显增大；扩展门槛值在氢蚀起始阶段显著降低，随后又呈增加趋势。对２．２５Ｃｒ－１Ｍｏ钢，由于元素Ｃｒ、Ｍｏ作用，其氢蚀程度远低于２０Ｇ钢，从而未造成疲劳裂纹扩展速率的明显改变。分析表明，氢蚀后疲劳裂纹扩展门槛值的上升     

2.25Cr-1Mo钢氢致裂纹扩展行为研究

采用电解充氢方法对2.25Cr-1Mo钢氢致裂纹扩展进行试验,并采用甘油测氢法测定了2·25Cr-1Mo钢发生裂纹扩展时钢中扩散的平均氢浓度.为了进一步了解裂纹尖端的氢浓度大小对裂纹扩展的影响,利用有限元软件对氢在2.25Cr.1Mo钢中的扩散过程进行模拟分析,系统研究了在应力-氢环境交互作用下裂纹尖端周围的氢扩散规律,并给出了裂纹扩展时裂尖局部位置的氢浓度大小.     

1(1/4)Cr—(1/2)Mo耐热钢焊接工艺试验

本文介绍美国引进的1(1/4)Cr—(1/2)Mo耐热钢匹配以国产焊丝、焊条的工艺评定试验及现场工程应用。     

KINETICS OF TEMPER EMBRITTLEMENT IN 2.25Cr-1Mo STEEL USED FOR HOT-WALL HYDROFINING REACTORS

Based on the theory of grain boundary segregation, a kinetics model of temper em-brittlement caused by long-term service for hot-wall hydrofining reactors was studied.The kinetics model was applied to phosphorus (P) segregation in 2.25Cr-1Mo steelused for a hot-wall hydrofining reactor, and the kinetics of grain boundary segrea-tion of impurity P in the steel exposed to the process environment of the hydrofiningreactor was calculated on the basis of the model. The Auger electron spectroscopytest was performed in order to determine the grain boundary concentration of P. Theexperimental result is agreement with the theoretical calculated data. The results showthat the kinetics equation is reasonable for predicting the levels of grain boundarysegregation of impurity P in 2.25Cr-1Mo steel used for hot-wall hydrofining reactors.     

KINETICS OF TEMPER EMBRITTLEMENT IN 2.25Cr-lMo STEEL USED FOR HOT-WALL HYDROFINING REACTORS

Based on the theory of grain boundary segregation,a kinetics model of temper embrittlement caused by long-term service for hot-wall hydrofining reactors was studied.The kinetics model was applied to phosphorus (P) segregation in 2.25Cr-1Mo steel used for a hot-wall hydrofining reactor,and the kinetics of grain boundary segregation of impurity P in the steel exposed to the process environment of the hydrofining reactor was calculated on the basis of the model.The Auger electron spectroscopy test was performed in order to determine the grain boundary concentration of P.The experimental result is agreement with the theoretical calculated data. The results show that the kinetics equation is reasonable for predicting the levels of grain boundary segregation of impurity P in 2.25Cr-1Mo steel used for hot-wall hydrofining reactors.     

2.25Cr-1Mo加氢反应器过渡段调质工艺的优化

在2.25Cr-1Mo加氢反应器过渡段常规调质工艺中增加亚温淬火,改善了大锻件的内部组织,细化了晶粒,提高了锻件的抗回火能力,使模拟焊后热处理(PWHT)后的力学性能显著提高.     

2.25Cr-1Mo与2.25Cr-1Mo-0.25V钢冷却转变对比分析

采用相变仪、光学显微镜及扫描电镜研究了2.25Cr-1Mo和2.25Cr-1Mo-0.25V钢冷却转变过程,并分析了钒对其冷却转变的影响。结果表明,与2.25Cr-1Mo钢的CCT曲线相比,2.25Cr-1Mo-0.25V钢铁素体转变区及贝氏体转变区均向右移,并且在现有试验条件下已无法观察到珠光体转变区;钒添加到2.25Cr-1Mo钢中,能够提高钢的淬透性,2.25Cr-1Mo-0.25V钢在48 000 ℃/h冷速下能生成部分马氏体;钒能够细化钢板显微组织,与2.25Cr-1Mo钢相比,2.25Cr-1Mo-0.25V钢在800 ℃/h冷速下组织更为细小。     

Microstructural modification in a laser-treated 2.25Cr-1Mo steel

A systematic study was carried out to understand the various microstructural changes in the heat-affected zone due to laser treatment on 2.25Cr-1Mo steel. The observed microstructures pertain to different cooling rates at different depths from the surface. A good correlation of the microstructures with the corresponding time-temperature-transformation (TTT) diagram of the steel was observed.     

稀土元素对2.25Cr-1Mo钢断裂性能的影响

本文用定量金相仪(QTM)和扫描电镜(SEM)测定含与不含稀土元素(RE)的2.25Cr-1Mo钢的夹杂物尺寸及分布;观察断口形态并测定延伸区宽度和韧窝尺度及分布;测定拉伸样品纵剖面上孔洞面密度与真应变的关系.研究表明,添加RE的试验钢中夹杂物密度较高,在较低的应变下沿夹杂物界面发生孔洞形核、长大和汇合,导致含RE的2.25Cr-1Mo钢较低的室温断裂性能.     

2.25Cr-1Mo不锈复合钢板厚壁容器的焊接

主要介绍了2.25Cr-1Mo不锈复合钢板的焊接工艺试验和工艺评定，阐明了2.25Cr-1Mo锈复合钢板焊接工艺的可行性，实践证明，该工艺能满足使用要求。     

2.25Cr-1Mo钢氢致开裂行为及回火脆对抗氢致开裂性能的影响

    采用电解充氢方法分别对回火脆态和脱脆态2.25Cr-1Mo钢氢致开裂行为进行实验研究,通过甘油测氢法测定了2.25Cr-1Mo钢发生裂纹扩展时钢中扩散的平均氢浓度.为进一步了解回火脆对抗氢致开裂性能的影响,利用有限元软件分别对氢在回火脆态与脱脆态2.25 Cr-1Mo钢中的扩散过程进行模拟分析,系统研究了在应力-氢环境交互作用下裂纹尖端周围的氢扩散规律,并给出了裂纹扩展时裂尖局部位置的氢浓度大小.     

20G和2．25Cr—1Mo钢氢蚀后的疲劳性能

对２０Ｇ和２．２５Ｃｒ－１Ｍｏ钢经不同程度氢蚀后的常规力学性能与疲劳裂纹扩展行为进行了对比研究。并对氢蚀组织变化与裂纹扩展路径进行了显微观察。结果表明，氢蚀使２０Ｇ钢的疲劳裂纹扩展速率明显增大；扩展门槛值在氢蚀起始阶段显著降低，随后又呈增加趋势，对２．２５Ｃｒ－１Ｍｏ钢，由于元素Ｃｒ，Ｍｏ的作用，其氢蚀程度远低于２０Ｇ钢，从而未造成疲劳裂纹扩展速率的明显改变，分析表明，氢蚀后疲劳裂纹扩展门槛值的上升可以归因于曲折开裂路径造成裂纹闭合效应的增加。