共查询到18条相似文献,搜索用时 46 毫秒
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AZ31镁合金的缺口冲击韧性及其断裂机理 总被引:2,自引:0,他引:2
缺口冲击韧性是金属材料应用的一个重要动态性能指标。本文针对AZ31镁合金板材,在-80~260℃范围内,进行了Charpy V型缺口冲击试验,测试了其缺口冲击韧性随温度变化的规律,试验结果表明:在120~160℃范围内,AZ31镁合金存在韧脆转变现象,根据能量标准和延性标准测得的韧脆转变温度均为140℃。并通过SEM手段对-80℃、0℃、80℃、140℃、200℃以及260℃等典型温度下的冲击断口形貌进行了比较分析,结果表明在-80~80℃范围内断口为准解理形貌;80~200℃范围内断口形貌是准解理+韧窝;200~260℃温度范围内断口是韧窝形貌。 相似文献
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16MnR 钢弹塑性断裂韧性Ji的韧脆转变温度特性 总被引:6,自引:0,他引:6
研完了16MnR钢弹塑性断裂韧性Ji的韧脆转变温度特性。结果表明,断裂韧性Ji的韧脆转变非常明显,其韧脆转变温度大大低于夏比冲击韧性的韧脆转变温度。根据试验结果,建议采用以弹塑性断裂韧性Ji的韧脆转变温度曲线为基础来确定受静载荷低温设备的最低使用温度。 相似文献
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用带有微机检索和处理数据的摆锤式冲击试验机测定了30CrMnSiNi2A钢的韧脆转变曲线,提出了判定韧脆转变的判据,解决了一般在超高强度钢中,因总冲击功随试验温度呈连续变化,没有明显的突变点而难于准确判定韧脆转变温度的困难。 相似文献
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通过系列温度冲击试验,采用V,U型缺口的试样,以冲击吸收功,纤维断面率结合断口微观形貌的变化对35CrNi3MoV钢的韧脆转变温度进行测定分析,试验表明:35CrNi3MoV钢韧脆转为温度为-60℃。 相似文献
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构建低活化铁素体/马氏体(RAFM)钢的中子辐照脆化预测模型对聚变反应堆的安全运行和优化设计新型RAFM钢具有十分重要的意义。本研究基于收集的RAFM钢中子辐照数据集,采用相关性筛选、递归消除方法识别出影响RAFM钢中子辐照条件下韧脆转变温度(DBTT)的关键特征变量。利用筛选的关键特征变量,构建了具有良好预测能力的RAFM钢中子辐照DBTT预测模型。为进一步实现中子辐照条件下韧脆转变温度变化(ΔDBTT)的预测,首先构建了RAFM钢未辐照DBTT预测模型,然后将辐照前后DBTT预测模型相结合构建了RAFM钢中子辐照ΔDBTT预测模型。通过将模型预测的ΔDBTT与文献收集的数据进行对比发现,该模型具备较好的预测能力。 相似文献
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制备钨合金面临着再结晶温度低、韧脆转变温度高、高温强度低及寿命短等问题。稀土氧化物氧化镧(La2O3)添加到钨合金内,再结晶温度提高、韧脆转变温度下降、高温强度提高,所以钨材料内添加La2O3是最近几年国内外的热门研究课题之一。主要介绍了高温强度强、再结晶温度低、寿命长的W-La2O3合金的最佳La2O3添加含量以及改善这些性质的一些方法,最后指出了该合金待解决的一些问题及其发展趋势。 相似文献
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马志青 《理化检验(物理分册)》2005,41(3):122-123
采用V型缺口试样,通过系列温度的冲击试验.以冲击吸收功、纤维断面率的变化对4130X钢的韧脆转变温度进行了测定。试验结果表明,4130X钢韧脆转变温度为-40℃。 相似文献
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Charpy V-notch impact toughness of 600 MPa yield stress TMT rebars alloyed with copper, phosphorus, chromium and molybdenum
has been evaluated. Subsize Charpy specimens were machined from the rebar keeping the tempered martensite rim intact. The
copper-phosphorus rebar showed toughness of 35 J at room temperature. The toughness of copper-molybdenum and copper-chromium
rebars was 52 J. The lower toughness of phosphorus steel is attributed to solid solution strengthening and segregation of
phosphorus to grain boundaries. Due to superior corrosion resistance, copper-phosphorus TMT rebar is a candidate material
in the construction sector. 相似文献
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Y. Q. Wang X. Y. Liu Z. W. Hu Y. J. Shi 《Fatigue & Fracture of Engineering Materials & Structures》2013,36(12):1258-1273
The thick plate induces the variation of mechanical properties and fracture toughness, especially in cold regions. At the low temperature, the brittle behaviour of steel becomes worse. A series of tests (such as uniaxial tensile test and three‐point bending test) were carried out at low temperature to investigate the mechanical properties and fracture toughness of structural steel plates of Q345B with thickness of 60 to 150 mm, as well as the fracture toughness of 150 mm thick butt welded plate. The test specimens are all manufactured from plates along thickness with small size, and the tensile test specimens included through‐thickness specimens additionally. The ductility index (percentage reduction of area) and the fracture toughness index (critical CTOD values) all decrease with the temperature decreases and the distance from plate surface increases. The results obtained in this paper provide technical basis for preventing brittle fracture of thick plate steel structures in cold regions. 相似文献
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为研究低温下结构钢断裂机理及抗断设防,在冷脆转换温度下(-45 ±2℃)对的个16mm厚Q345钢材缺口板进行了单向拉伸断裂试验,研究了缺口尺寸(a、2b)对结构钢断裂模式的影响.结果表明:试件断裂于刻痕心部,断口心部有一条清晰的起裂棱,宏观断面大致垂直于加载方向;试件缺口愈尖锐或缺口比率(2b/a)愈小,断裂延性愈差... 相似文献
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为比较不同摆锤刀刃锤头对冲击试验结果的影响,采用8mm摆锤刀刃锤头和2mm摆锤刀刃锤头对X65管线钢进行系列夏比冲击试验,对测得的冲击能量进行比较分析。结果表明:在较高的能量范围内,采用8mm摆锤刀刃比采用2mm摆锤刀刃测得的冲击吸收能量高;随着试验温度的降低,两种不同摆锤刀刃下的冲击吸收能量值均逐渐减小,采用8 mm摆锤刀刃测得的冲击吸收能量下降更多;在较低的能量范围时,两者之间的差值变小;采用8 mm摆锤刀刃确定的韧脆转变温度高于采用2 mm摆锤刀刃确定的韧脆转变温度。 相似文献
15.
两种焊接工艺对焊接接头冲击韧度的影响 总被引:1,自引:0,他引:1
封树德 《理化检验(物理分册)》2010,(9):560-562
针对对接焊缝金属的冲击吸收功低于熔敷焊接接头中的熔敷金属的冲击吸收功的现象,分别从材料的力学性能和显微组织方面进行探讨。结果表明:对接焊缝金属中的屈氏体含量高于熔敷金属中的含量,组织较粗大,从而使得对接焊缝金属容易形成裂纹,致使相同温度下对接焊缝金属与熔敷金属相比其冲击吸收功较低,韧性-脆性转变温度较高。 相似文献
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J. D. G. Sumpter 《Advanced Performance Materials》1996,3(3-4):393-405
Shipbuilders are showing increasing interest in laser welding as a means of reducing fabrication costs. The nature of the weld zone is very different to that in an arc weld. Careful research is needed to establish the safety of laser welded structures against a range of risk scenarios. This report deals with fracture toughness and defect tolerance. The laser weld is shown to exhibit very unusual behaviour. The lowest toughness is obtained when a crack is located at the heat affected zone (HAZ), but there is no apparent microstructural embrittlement at this location. It is proposed that the effect arises from an elevation of crack tip tensile stresses induced by the strength overmatch of the adjacent weld zone. 相似文献
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V. V. Kharchenko E. A. Kondryakov V. N. Zhmaka A. A. Babutskii A. I. Babutskii 《Strength of Materials》2006,38(5):535-541
The Charpy impact tests were carried out at different temperatures and loading rates. The temperature dependences of crack
initiation and propagation in carbon steels 45 and St. 3 under impact testing were determined from the obtained force variation
plots. The effect of the impact velocity in the range from 1 to 4.4 m/s on the fracture toughness temperature dependence is
estimated.
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Translated from Problemy Prochnosti, No. 5, pp. 120–127, September–October, 2006. 相似文献