热轧H型钢翼缘斜度控制方法及措施

介绍了H型钢主流生产工艺和设备特点,针对国内某钢厂大H型钢产线出现的产品翼缘斜度超标现象进行原因分析,结合设备工作特点和现场跟踪表明,H型钢翼缘斜度超标分通长超标和仅轧件头部超标两种情况,通长超标与热轧过程中精轧机轧制线和其前后摆动辊道的相对位置有关,轧件头部翼缘斜度超标与锯切工序设备状况有关,同时轧件温度、矫直条件等...     

辐射离散坐标法在柱形炉膛中的辐射传热计算

利用离散坐标法对圆柱形炉膛辐射传热进行了计算,结果与计算精确的区域法的计算结果符合较好;同时又利用离散坐标法和热流法对旋流燃烧室温度场进行比较计算,结果表明:离散坐标法计算结果与文献中实验结果符合较好;离散坐标法具有较好计算精度,可应用旋流燃烧辐射计算中.     

燃烧器的改进对FAAS法测定地质样品中金的检出限影响

通过对火焰原子吸收分光光度计的燃烧器进行改进,即在燃烧头狭缝的两侧分别放置1块由耐火材料制成的挡板,从而有效地降低了燃烧头火焰波动。在采用FAAS法测定地质样品中的金时,通过使用不同挡板高度和调整两挡板间距离进行了对比实验;分析结果表明,对燃烧器的优化改进可以有效地提高测定结果的稳定性和可靠性,从而也可以降低FAAS法测定地质样品中金的检出限。     

Orientation distribution function analysis of the recrystallization texture in a boron-treated deep-drawing steel

The textural components present in a boron-treated deep-drawing quality nonaging steel, processed and annealed in the mill, have been determined using the orientation distribution function (ODF) analysis technique. The main components are a 〈111〉 fiber parallel to sheet plane normal or normal direction, ND, and an incomplete 〈337〉∥ND fiber. Minor {110}〈001〉, {310}〈001〉, {001}〈110〉, and {110} 〈110〉 orientations were also found. The texture on the whole is somewhat similar to that in A1-killed steels, but not as strongly developed. It is expected that this boron-treated steel would be suitable for moderate forming applications.     

Mixed group validation: A method for determining the validity of diagnostic signs without using criterion groups.

To determine whether a sign x distinguishes between X-type and Y-type individuals (Y = not-X), it is necessary to obtain estimates of p(x/X), the probability an X-type shows sign x, and p(x/Y). The traditional method for determining these probabilities, criterion-group validation, involves observing the incidence of x in 1 group consisting entirely of X-types and in a 2nd group consisting entirely of Y-types. Here, equations are developed for obtaining these probabilities by observing the incidence of x in any 2 groups having different, known base rates of X-types. The validation procedure making use of these equations is termed mixed-group validation, and it is pointed out that criterion-group validation is a special (limiting) case of mixed-group validation. Advantages of mixed-group validation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

钢管斜辊矫直机辊形的一种空间算法及应用

矫直辊是斜辊矫直机上用于矫直钢管的工模具,辊形为特殊曲面,辊形设计直接决定了矫直效果。介绍了钢管斜辊矫直的工作原理及对矫直辊辊形的理论要求,选取了研究对象并建立坐标系,以矫直辊和基准钢管的空间接触曲线几何特性分析为基础,通过一系列数学路径,推导出空间接触曲线、辊形曲面、辊形母线的方程式,对辊形曲面的几何性质进行了描述。将所描述方法推导出的空间接触曲线方程式和基于共轭运动啮合原理算法推导出的空间接触曲线方程式进行了统一,实现了算法间的理论印证。利用推导出的方程式,对某一规格矫直机的辊形母线进行了数据计算和数值处理,介绍了数值处理的方法及效果。将该算法在某新建工程的3台矫直机辊形设计中进行应用,现场检测表明,在基准条件下,设计的辊形和样管的接触度良好,生产中矫直效果良好。     

钢管斜辊矫直机辊形的一种空间算法及应用

矫直辊是斜辊矫直机上用于矫直钢管的工模具,辊形为特殊曲面,辊形设计直接决定了矫直效果。介绍了钢管斜辊矫直的工作原理及对矫直辊辊形的理论要求,选取了研究对象并建立坐标系,以矫直辊和基准钢管的空间接触曲线几何特性分析为基础,通过一系列数学路径,推导出空间接触曲线、辊形曲面、辊形母线的方程式,对辊形曲面的几何性质进行了描述。将所描述方法推导出的空间接触曲线方程式和基于共轭运动啮合原理算法推导出的空间接触曲线方程式进行了统一,实现了算法间的理论印证。利用推导出的方程式,对某一规格矫直机的辊形母线进行了数据计算和数值处理,介绍了数值处理的方法及效果。将该算法在某新建工程的3台矫直机辊形设计中进行应用,现场检测表明,在基准条件下,设计的辊形和样管的接触度良好,生产中矫直效果良好。     

惰气熔融热导法测定钢铁中氮的不确定度评定

对惰气熔融热导法测定钢铁中氮的不确定度的产生原因进行了分析,并对一个钢样中氮的不确定度进行了评定,给出评定结果.     

A method for determining the productivity of electrolyzers for aluminum production

The existing methods for determining the productivity of aluminum electrolyzers are systematized. It is shown that the metal-indicator method with copper used as the indicator metal is the most suitable for industrial conditions. The kinetics of dissolution of copper in industrial aluminum electrolyzers is studied and a formula for calculating their productivity is derived. The optimal charge weight of the indicator metal (copper) and the volume of sampling (the number of electrolyzers) are established.     

A rapid method for determining the particle-size distribution of micropowders

Conclusions Use of a flow-type laser analyzer in an investigation of the particle size distribution of a powder markedly accelerates analysis and enables the latter to be performed automatically, with the recording of numerical characteristics and forms of distribution functions for particles ranging in size from a few hundreds of angstrom units to some tens of micrometers. It is shown that the distribution functions of the particles of titanium carbide powders produced by comminution in a ball mill and subsequent liquid centrifugal classification into 3–5-, 2–3-, and 1–3-m fractions obey the logarithmic normal law. The numerical characteristics of these distributions are given.Translated from Poroshkovaya Metallurgiya, No. 11(263), pp. 10–14, November, 1984.     

A method for determining types of self-esteem.

"The present study describes a method of determining self-esteem. This method is based upon a conbination of (a) the subject's response to the Self-Esteem Inventory; (b) a rating of certain of his behaviors which are presumably related to self-esteem; and (c) information on a constellation of experiential and motivational variables." 22 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A mathematical method for the calculation of ledge growth kinetics

A method outlined in a recent paper by Atkinson and Wilmott¹ is applied here to the transient motion of a finite train of steps, particular attention being given to two-and three-step trains where the steps are sufficiently far apart. The resulting integro-differential equations which govern the step motions are solved numerically for some model situations, and some qualitative agreement with the extensive numerical calculations of Enomoto^2,3 is found. Equations are also derived for the case when two steps come close together, but numerical implementation of this case is still to be made. This paper is based on a presentation made in the symposium “The Role of Ledges in Phase Transformations” presented as part of the 1989 Fall Meeting of TMS-MSD, October 1–5, 1989, in Indianapolis, IN, under the auspices of the Phase Transformations Committee of the Materials Science Division, ASM INTERNATIONAL.     

中、薄板带钢冷连轧轧制力便捷计算法研究

轧制力计算有多种模型,大多存在计算繁琐、工作效率低下的问题。通过对冷连轧多种轧制力计算模型的对比研究,针对中、薄板带钢大压下率的M.D.Stone计算模型,采用最小二乘法对轧制力进行曲线拟合,找出一种便捷的算法——轧制力曲线拟合算法,通过一般的计算器或程序即可对轧制力进行求解。应用效果表明,该算法能使轧制力预报精度和计算效率大幅提高,为轧制力预报提供了一条更加便捷、可靠的途径。     

Modeling the heat flow in spray formed steel shells for tooling applications

This article concerns a metal spraying process for the manufacture of production tooling at reduced time and cost. Critical to the successful operation of this process is control of the sprayed steel shell temperature to eliminate thermal residual stresses and distortion. A computational model of the transient heat flow in steel shells during spray forming has been developed. The critical data for the distribution of convective heat-transfer coefficient distribution over the shell surface and average spray temperature has been obtained from experiments using embedded calorimeters and process monitoring respectively. Shell average temperature and temperature variance have been investigated using the model, and predictions compared well with experimental measurements obtained using infrared thermal imaging. The wire feed rate was identified as the most suitable control parameter for a closed loop control system to regulate shell surface temperature during manufacture.