共查询到20条相似文献,搜索用时 46 毫秒
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低合金钢中非金属夹杂物的检测与表征, 需要解决夹杂物分析的代表性和准确性问题。实验以脉冲分辨分析方法确定了低合金钢中非金属夹杂物的组分, 并研究了其单火花脉冲分布和图谱。采用定量金相、扫描电镜和能谱仪等多种物理分析手段对目标夹杂物进行全面分析, 探讨了夹杂物的主要存在状态和异常光谱信号与夹杂物的颗粒数量、尺寸之间的相关性。研究发现单位面积内夹杂物的尺寸越大, 对异常火花相对频数和异常平均强度占总体平均强度的比例影响越大。在对低合金钢进行常量元素含量检测的同时, 通过单火花脉冲分布和图谱还能对非金属夹杂物进行识别和检测, 结合金相和扫描电镜物理分析手段实现了非金属夹杂物的定量和定性, 适用于对低合金钢的日常质量控制。 相似文献
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研究了钢中硅系夹杂物的颗粒尺寸测定的原位统计分布新方法。结合定量金相和扫描电镜多种物理分析手段,探讨了原位火花光谱中元素硅的异常光谱信号与硅夹杂物的颗粒数量、尺寸之间的相关性,发现钢中单位面积内尺寸大于3μm的夹杂物颗粒个数对异常火花相对频数影响较大,异常平均强度占总体平均强度的比例也与大于3μm的硅系夹杂物的平均粒径密切相关,由此建立了相应的数学模型来计算钢中较大颗粒硅系夹杂物的数量、平均粒径和最大平均粒径。将方法应用于多种钢样品中硅系夹杂物颗粒的状态分析,所得结果与定量金相分析结果具有良好的对应关系。 相似文献
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采用原位统计分布分析技术对钢中硅系夹杂物的含量进行了分析。结合物理化学相分析、扫描电镜和能谱仪等多种物理化学分析手段,探讨了原位火花光谱中元素硅的异常光谱信号与硅系夹杂物的数量之间的相关性,提出了夹杂硅的原位统计定量分析参数,并建立了夹杂硅含量的原位统计定量模型。同时采用通道合成技术对硅系夹杂物的组成进行了定性分析,并将所得的数学模型应用于多种不同成分的中低合金钢样品中硅系夹杂物的分析,所得结果与扫描电镜分析结果和物理化学相分析测定结果具有较好的一致性。 相似文献
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钢中夹杂物对钢铁材料的性能存在着重要的影响,钢水中凝固的夹杂物会降低钢的物理性能。为排除钢中夹杂物的影响,需要建立检测夹杂物的方法。基于重轨钢样品中铝夹杂物的异常信号响应及阈值选择,实验研究了一种新的钢中铝系夹杂物含量的激光诱导击穿光谱分析(LIBS)检测方法。由于钢材中夹杂铝大多以酸不溶铝的形式存在,故研究中采取的计算模型中夹杂铝的含量默认与酸不溶铝含量相同。实验中由于检测的中低合金钢中夹杂铝含量过低,故随机选择9块重轨钢待测样中5块作为标准样品,通过结合LIBS结果中异常信号的筛选和已发表文献的模型进行计算,发现在置信区间阈值K=2.6时,激光诱导击穿光谱法得到的结果中夹杂物计算值与真实值基本符合,由此确立了激光诱导击穿光谱对铝夹杂分析的计算数学模型。将所建立的夹杂物检测方法模型实际应用于剩余4块重轨钢样品的检测,并将测定结果与化学湿法进行结果比对,结果显示二者基本一致。 相似文献
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在不同的温度条件下对电解二氧化锰进行中和处理,用半电池模拟放电试验(half—cell)检测其放电情况,进而探讨中和温度对电解二氧化锰电性能的影响。 相似文献
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电化学法处理铜冶炼废水的应用和实践 总被引:1,自引:0,他引:1
为了提高废水处理能力,保证废水稳定达标排放,江铜集团贵溪冶炼厂在硫酸车间应用电化学法处理含重金属废水工艺实践,取得了较好的效果,较原有"中和絮凝沉淀"化学法处理后的排放水指标达标率和稳定性有明显提高,减轻了员工的劳动强度。同时也对电化学运行中存在的问题提出了新的解决方法。 相似文献
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介绍了电解铜粉生产过程中产生的含铜、含酸废水处理,以及污泥综合利用,实现资源再循环。经济效益、社会效益、环境效益显著。 相似文献
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采用不同的烧结温度和烧结压力对Ti-6Al-4V-0.5In钛合金汽车零件试样进行放电等离子烧结处理,研究了烧结工艺对试样耐磨损性能和冲击性能的影响。结果表明:随烧结温度的提高和烧结压力的增大,试样的耐磨损性能和冲击性能均先提高后下降。钛合金汽车零件材料的烧结温度优选为875℃,烧结压力优选为45 MPa。 相似文献
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ICP—AES法同时测定金属锌中的铅,铁,镉,铜,锑 总被引:1,自引:1,他引:0
针对金属锌中杂质元素分析, 选择了最佳仪器条件, 拟定了加入内标元素的方法,用ICP- AES法同时测定题示元素, 测定结果能满足生产需要。 相似文献
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环境标准是环境保护法规的有机组成部分,是环保部门行使管理职能的依据,是环境评价的准绳,同时也是建设项目环保设计和企业进行内部环境管理的重要依据。环境质量标准与污染物排放标准是我国环境标准体系的主体,都是强制性标准,该文主要对污染物排放标准使用过程中应注意的一些问题进行了探讨。 相似文献
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Empirical data indicate that hydraulic geometry relationships for single-thread sand-bed rivers (i.e., rivers with median bed-material size between 0.062 and 0.50?mm) can be delineated such that bankfull width, bankfull depth, and channel slope are related in consistent ways to bankfull discharge. Such relationships ought to be the external expression of physical relationships intrinsic to sand-bed river dynamics. In this study, a back-calculation is performed to identify parameters (exponents and coefficients) for three relationships taken to be intrinsic to sand-bed rivers: (1)?a generalized Manning-Strickler resistance relationship; (2)?a relationship for channel-forming Shields number; and (3)?a relationship for sand yield at bankfull flow. To back-calculate parameters for the physical relationships, first the hydraulic geometry relationships are expressed in suitable dimensionless form. Second, the physical relationships are expressed with coefficients and exponents that are analytically related to parameters in the hydraulic geometry relationships. Third, parameters from the hydraulic geometry relationships are used to calculate parameters for the physical relationships. The analysis yields the following results for the sand-bed rivers: (1)?no physical basis exists for using an exponent of 1/6 in the resistance relationship; (2)?channel-forming Shields number decreases with particle Reynolds number, and thus grain size, in a consistent way; and (3)?sand concentration at bankfull flow must decline with increasing bankfull discharge. Although each of these relationships could have been established independently on its own, in this study they have been obtained as the only conclusions consistent with the observed hydraulic geometry relationships and the proposed physical framework. The analysis also yields a useful, dimensionally homogeneous predictive relationship for bankfull discharge as a function of bankfull width, bankfull depth, bed slope, and bed-material median grain size. 相似文献
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A two-dimensional numerical model was developed to simulate relatively wide, shallow rivers with an erodible bed and banks composed of well-sorted, sandy materials. A moving boundary-fitted coordinate system was used to calculate water flow, bed change, and bank erosion. The cubic interpolated pseudoparticle method was used to calculate flow, which introduced little numerical diffusion. The sediment-transport equation for the streamline and transverse transport was used to estimate bed and bank evolution over time, while considering the secondary flow. Bank erosion was simulated when the gradient in the cross-sectional direction of the banks was steeper than the submerged angle of repose because of bed erosion near the banks. The numerical model reproduced the features of central bars well, such as bar growth, channel widening due to divergence of the flow around the bars, scour holes at the lee of the bars, and the increase of bar size with time. These features were in accordance with the observations for laboratory experiments. It also reproduced the features of braided rivers, such as the generation of new channels and abandonment of old channels, the bifurcation and confluence of channels, and the lateral migration of the channels. The model showed that the sediment discharge rate fluctuated with time, one of the dynamic features observed in braided channels. 相似文献