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本文研究了涂有NaCl+Na2SO4混合盐膜的P122钢焊接接头,在650℃空气中的热腐蚀行为.采用X-射线衍射和EDX能谱对腐蚀产物进行了分析.试验结果表明,在650℃增加氯化钠的含量,腐蚀速率增加,焊接接头表面形成疏松的氧化层.此外还探讨了P122钢焊接接头的热腐蚀机制. 相似文献
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通过合理地设计P91钢的焊接工艺,对给定焊接条件下其焊接接头的显微组织特征和冲击韧性进行了研究.结果表明,采用所制定的焊接工艺,可以使焊接接头的显微组织均变为回火板条马氏体,且使焊缝晶粒明显细化并接近于母材晶粒;可获得良好冲击韧性,焊接接头热影响区的冲击值与母材相当,焊缝的平均冲击值为116.3 J,且所测量的实验值均高于现有标准. 相似文献
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采用手工电弧焊(SMAW)对P22钢管进行全截面对接焊,测试分析焊接接头的组织结构、抗拉强度、弯曲性能、硬度和夏比V型冲击性能。结果表明:焊接接头质量良好,抗拉强度为515 MPa,侧弯试样均无裂纹;20℃下焊缝、热影响区和熔合线的冲击吸收能量分别为150 J、317 J、305 J,焊缝区、热影响区硬度分别为213~223 HV10、185~223 HV10;力学性能均符合BS EN ISO 15614-1∶2004+A2∶2012标准;焊缝、热影响区显微组织分别为粒状贝氏体和铁素体+粒状贝氏体,且热影响区可分为过热重结晶区、重结晶细晶粒区和不完全重结晶区;接头不同区域的组织结构与硬度分布相符。 相似文献
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以T/P91钢为研究对象,在连续介质损伤力学模型(CDM)基础上研究了T/P91钢蠕变机制。通过计算机仿真和文献实验结果分析可知,模拟T/P91钢材的蠕变曲线必须考虑空洞形核长大、溶质原子贫化以及Laves相粗化等损伤影响,才能获得比较真实的蠕变曲线。 相似文献
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P92����Laves��ǿ�����õ��о� 总被引:1,自引:0,他引:1
采用化学定量相分析技术并借助于光学显微镜、XRD、SEM、TEM及常规的力学检测设备,研究了600 ℃下P92钢中Laves相对强度的影响规律,结果表明:Laves相在时效过程中析出,时效时间在100 h 内, Laves相快速形核, 1 000 h内,随着时效时间的延长,钢中Laves相含量逐渐增加并能有效提高P92钢室温和600 ℃高温强度;600 ℃下3 000 h内提高P92钢中狂钨、钼含量,增加Laves相的析出量,能够显著提高P92钢持久强度。 相似文献
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针对马氏体耐热钢 10Cr9Mo1VNbN和珠光体耐热钢 12Cr1MoV ,采用TGS -9cb、H10Cr5Mo、TR31三种焊丝形成高、中、低匹配焊接接头 ,利用脉冲电流氩弧焊、高温加速模拟工况、力学性能试验及电子显微分析 ,研究了 10Cr9Mo1VNbN/ 12Cr1MoV异种钢焊接接头的力学性能、高温强度、界面蠕变损伤及失效特征。试验结果表明 ,焊前预热 2 5 0℃ ,焊后回火 75 0℃× 1h ,加速模拟运行 5 0 0h后 ,高匹配和中匹配接头的力学性能劣化明显 ,界面蠕变损伤及失效倾向较大 ;而低匹配接头的力学性能优于高匹配和中匹配接头 ,界面蠕变损伤较轻 ,失效倾向较小。因此 ,选用TR31焊丝作为10Cr9Mo1VNbN/ 12Cr1MoV异种钢焊接接头的填充材料较为合适。 相似文献
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P92钢焊接接头蠕变本构关系 总被引:1,自引:1,他引:0
通过热处理方法模拟焊接热循环,在 3.53 K/s 的升温速度下制备 P92 钢焊接热影响区各微区的模拟组织试样,通过单轴蠕变试验获得 923K 下 P92 钢熔敷金属、热影响区各微区和母材组织不同应力水平下的单轴蠕变数据,用最小二乘法拟合得到 P92钢焊接接头各区域组织在稳态蠕变条件下的蠕变本构方程.结果表明,相比焊接接头其它微区组织,试验应力较低时,细晶区的蠕变应变率最大,因此在低应力下细晶区容易发生蠕变开裂;随着应力水平的增加,焊接接头和母材蠕变速率逐渐超过细晶区,蠕变断裂易发生在焊缝或母材上.Abstract: The welding heat thermal cycle was simulated through the heat treating method, and the simulated microstructures of the coarse grain heat-affected zone (CGHAZ), fine grain heat-affected zone (FGHAZ) and intercritical heat-affected zone (ICHAZ)of P92 steel were prepared by using a furnace at 3.53 K/s of heating rate. The uniaxial creep data of the base metal, deposited metal and simulated CGHAZ, FGHAZ and ICHAZ specimens were obtained through the creep tests under the temperature of 923 K, and the creep constitutive equations of each material were obtained too. The result shows that the creep strain rate of FGHAZ is higher than the other zones of the welded joint under the low stress. So the creep rupture is easy to occur in te FGHAZ. In addition, the creep properties are obviously different among the CGHAZ, FGHAZ and ICHAZ, which indicate the HAZ has the obvious material heterogeneity. 相似文献
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Guo Donghui Zheng Zhentai Yu Jinling He Meng Shi Fen Li Shuai 《Metal Science and Heat Treatment》2021,63(5-6):280-288
Metal Science and Heat Treatment - The microstructure and mechanical properties of a welded joint from heat resistant steel SA-335 P5 have been studied directly after welding (as-welded), after... 相似文献
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对P355NL1钢焊接接头进行超声冲击处理,研究超声冲击对腐蚀疲劳性能的影响。利用光学显微镜和扫描电镜对超声冲击前后的表层显微结构以及腐蚀疲劳失效断口进行分析,利用电化学工作站对超声冲击前后试样电化学腐蚀速率进行测定。结果表明,当试样处于6%(质量分数) NaCl腐蚀溶液中时,焊态试样疲劳强度下降12.5%;在6%NaCl腐蚀液和水介质中,冲击态试样相较于焊态试样疲劳强度分别提高了75%和53%,S-N曲线斜率分别改变75.4%和60.4%。经超声冲击处理后试样表层产生明显的塑性变形层,最大变形层深度约350μm;冲击之后试样的疲劳寿命有很明显提高,疲劳断裂位置也由焊趾处转移到焊缝或者母材区,腐蚀坑数目明显减少。表明超声冲击可以细化晶粒,同时降低应力集中现象,消除有害残余拉应力,引入有益的残余压应力,降低电化学腐蚀速率,提高焊接接头的腐蚀疲劳性能。 相似文献
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M. D. Mathew Naveena D. Vijayanand 《Journal of Materials Engineering and Performance》2013,22(2):492-497
Impression creep tests have been carried out at 923 K on 316LN SS containing 0.07, 0.14, and 0.22 wt.% nitrogen, under different applied stress levels. It was observed that the impression creep depth versus time curves were similar to the creep curves obtained from conventional uniaxial creep tests. The impression creep curves were characterized by a loading strain and primary and secondary creep stages similar to uniaxial creep curves. The tertiary stage observed in uniaxial creep curves was absent. The steady-state impression velocity was found to increase with increasing applied stress. The equivalent steady-state creep rates calculated from impression velocities were found to be in good agreement with the steady-state creep rates obtained from conventional uniaxial creep tests. Equivalence between applied stress and steady-state impression velocity with uniaxial creep stress and steady-state creep rate, respectively, has been established based on the laws of mechanics for time-dependent plasticity. It was found that impression velocity was sensitive to the variation in nitrogen content in the steel; impression velocity decreased with increasing nitrogen content, and the results obtained in this study were in agreement with those obtained from uniaxial creep tests. 相似文献