美国TAPPI和PIMA合作下月出版一本新的正式出版物“Solutione—for People,Processes and Paper”

美国制浆造纸工业技术协会(TAPPI)总裁Michael D.Wallace和美国造纸工业管理协会(PIMA)总裁C.Rick Larrick宣布9月份联合出版一种新的正式出版物,以应对当今的挑战和机遇。

Removal of TOC and Color in Bleaching Effluents from Straw Pulp and Paper Mill by Fe^0-H_2O_2 Process

TOC and color in the bleaching effluent from straw pulp paper process could not reach draining standard after its treatment by a biochemical process. In this study, advanced treatment by integrated micro-electrolysis （Fe^0） method and Fenton-like process was investigated under various conditions, i.e. pH, Fe/C ratio, initial I-I2O2 concentration and carrier gas. Results showed that Fe/C ratio（V/V = 1.5）, larger H2O2 dosage around 50 rag/L, lower pH（pH= 3） turned out to be particularly efficient. Temperature was a key parameter, remarkably increasing reaction rates. Carrier air not only improved reaction efficiency, but also saved H2O2 dosage. Chlorinated organic compounds could be reductive dechlorinated by Fe^0 reaction and oxidated by OH produced from Fenton process. The combination of Fe^0 and H2O2 reactions had been proved to be highly effective for the advanced treatment of such a type of wastewaters, and important advantages concerning the application in the study.

Optimization study of station track utilization in high-speed railroad based on constraints of control in random origin and process

Purpose-The purpose of this paper is to eliminate the fluctuations in train arrival and departure times caused by skewed distributions in interval operation times.These fluctuations arise from random origin and process factors during interval operations and can accumulate over multiple intervals.The aim is to enhance the robustness of high-speed rail station arrival and departure track utilization schemes.Design/methodologylapproach-To achieve this objective,the paper simulates actual train operations,incorporating the fluctuations in interval operation times into the utilization of arrival and departure tracks at the station.The Monte Carlo simulation method is adopted to solve this problem.This approach transforms a nonlinear model,which includes constraints from probability distribution functions and is difficult to solve directly,into a linear programming model that is easier to handle.The method then linearly weights two objectives to optimize the solution.Findings-Through the application of Monte Carlo simulation,the study successfully converts the complex nonlinear model with probability distribution function constraints into a manageable linear programming model.By continuously adjusting the weighting coefficients of the linear objectives,the method is able to optimize the Pareto solution.Notably,this approach does not require extensive scene data to obtain a satisfactory Pareto solution set.Originality/value-The paper contributes to the field by introducing a novel method for optimizing high-speed rail station arrival and departure track utilization in the presence of fluctuations in interval operation times.The use of Monte Carlo simulation to transform the problem into a tractable linear programming model represents a significant advancement.Furthermore,the method's ability to produce satisfactory Pareto solutions without relying on extensive data sets adds to its practical value and applicability in real-world scenarios.

The Protection and Inheritance of the Traditional Papermaking Process: A Case Study of the Zhang Paper Workshop

The Zhang Paper Workshop preserving the complete traditional papermaking process has been praised by experts as “the living fossil of Chinese papermaking”. Due to the impact of industrial papermaking, however, the traditional papermaking has gradually lost its market advantage, and the Zhang Paper Workshop prevailing for a time is already on the decline. In order to retain this precious cultural heritage, for more than 10 years, the Gleaners has spared no effort to provide various efforts to papermakers and has found a way out for the manual papermaking, and results have been achieved. How to protect and inherit the traditional papermaking process under the premise of conserving the ecological environment and maintaining the integrity of the papermaking process, and establish the Zhang Paper Workshop as a place for spreading the concept of nature conservation and cultural heritage protection is an urgent problem to be solved. This requires the support of policies, the investment of funds and the upgrading of technology, as well as the promotion of understanding and the cultivation of feelings.

Structures and Properties of Iron Matrix Composites with Tungsten Carbide Particle by EPC-V Process

In this paper the Expendable Pattern Casting with dry sand Vacuum(EPC-V) process is used to manufacture iron matrix composites with tungsten carbide particle.Microstructures of the composites layers were analyzed.The abrasive wear resistance of the composites layers were tested and compared with that of high chromium cast iron.The results show that the iron matrix composites with tungsten carbide particle have high hardness.The abrasive wear resistance of composites with tungsten carbide particle is higher than that of high chromium cast iron.The properties of the matrix materials have been improved remarkably.

Relay Feedback Based Autotuning PID Control of Paper Basis Weight in Paper Making Process

The brief arts and crafts of the ordinary fourdrinier are introduced first. After the intractable points of paper basis weight (BW) control are analyzed, an autotuning PID/PI control algorithm based on relay feedback identification is proposed, which has such advantages as simple parameter adjustment, little dependence on process model, strong robustness and easiness to implementation. And it is very suitable for controlling such processes as BW loop with large time delay.

A MECHANICAL MODEL FOR THE DRY BASIS WEIGHT PLANT OF PAPER MAKING PROCESS

Of the two methods of getting the mathematical model of a given system,modeling and i-dentification,the first is of the advantage of“knowing it in the detailed inside”.In this paper,after the common technological process of paper making is approached,a simplified physicalimitation and the mathematical model are presented.The resulted model by means of modelingis of the same form with that through,identification by K.J.Astrom in 1970.The course ofmodel deriving is described in detail,from which one can see clearly how the minor factors ofthe dynamics are omitted and what may be included in the unmodeled dynamics.At the sametime,the limit to its usage is also given.

Development of high elongation steels by quenching and partitioning process

Based upon the composition of C-Si-Mn,four types of transformation induced plasticity（ TRIP） steels with different contents of Si and M n were designed,which are subjected to quenching and partitioning（ Q＆P）processes with variable austenitizing temperatures. The as-treated steels exhibits good combination of high strength and substantial elongation. In particular,with austenitizing at 820 ℃,0. 18C-1. 8Si-2. 2M n（ %） steel and0. 18C-1. 8Si-2. 5M n（ %） steel possessed high elongation（ more than 20%） with the tensile strength over 1000 M Pa. The microstructures of the as-treated steels were obtained by scanning electron microscope,the volume fraction and carbon content of retained austenite has been quantified by X-ray diffraction. The designed Q＆P processed steels contained a multiphase microstructure including ferrite,lath martensite,and retained austenite. The volume fraction and carbon content of those steels were higher,which was treated by Q＆P processes with austenitizing at 820 ℃. Due to the TRIP effect during the deformation process,retained austenite gives better stability as well as effectively improves the formability of steels with slightly decreasing the strength,contributing to overall better performance.

高强度冷轧TRIP钢的工艺改进及组织性能

采用轧制结合Gleeble-3500热模拟试验机模拟连续退火,研究了以低温卷取和中间退火为主要特征的改进工艺对冷轧TRIP钢组织和力学性能的影响。结果表明,低温卷取有利组织细化,中间退火工艺在降低冷轧抗力的同时有利提高钢在最终退火后的残留奥氏体量。等温淬火温度不同时,贝氏体形态与残余奥氏体量均不同,在400～420℃时可获得较高体积分数的残余奥氏体。改进工艺配合适当热处理工艺参数(420℃×5 min)条件下,实验冷轧TRIP钢的抗拉强度达到1030 MPa,总伸长率保持20%,综合性能优良。

TRIP钢中残余奥氏体及其稳定性的研究

采用扫描电镜、透射电镜、X射线衍射仪等对贝氏体等温转变后TRIP钢中的残余奥氏体及其稳定性进行了研究。结果表明,TRIP钢在贝氏体转变区400℃～440℃下保温120～300 s,随着等温温度的升高和保温时间的延长,钢中残余奥氏体的含量不断增多、残余奥氏体碳含量大致呈降低趋势。TRIP钢中的残余奥氏体主要以薄膜状、粗大块状和细小粒状的形态存在。粗大块状的残余奥氏体稳定性最差,薄膜状次之,细小粒状最稳定。残余奥氏体的含量不足,或残余奥氏体的含量偏高造成碳含量的不足,都会导致TRIP钢综合成形性能的降低。此外,贝氏体等温处理时间过长,渗碳体的出现大大降低了残余奥氏体中的碳含量,从而降低了残余奥氏体的稳定性。

相变诱导塑性TRIP钢的研究进展

相变诱导塑性(TRIP)钢是一种高强汽车用钢,一般通过热轧控制冷却或冷轧+热处理工艺进行生产,其组织由铁索体+贝氏体+残余奥氏体组成。本文介绍了TRIP钢的组织、性能特点及其生产工艺,对TRIP钢研究趋势做了展望。

高强中锰TRIP钢的残余奥氏体含量及其稳定性

设计了一种中锰相变诱导塑性(TRIP)钢,利用全新的热处理工艺对其进行处理,研究了其残余奥氏体含量及其稳定性,并对该钢的显微组织和力学性能进行了分析。结果表明:中锰TRIP钢退火后的残余奥氏体体积分数均在39%以上,且奥氏体在变形过程中绝大部分转变为马氏体,提高了钢的塑性和强度;在630℃退火可使该钢的抗拉强度大于1 000 MPa,伸长率大于30%,强塑积大于30GPa.%,残余奥氏体体积分数为51.4%。

Q&P工艺对TRIP800钢组织和力学性能的影响

采用盐浴法对Al含量较高的TRIP800钢进行了Q&P(quenching and partitioning)工艺处理,研究淬火终点温度和分配时间对试验钢的显微组织、力学性能和残留奥氏体含量的影响。结果表明:试验钢的显微组织为铁素体基体上分布着块状马氏体或马氏体-奥氏体的混合组织,随着淬火终点温度的降低或分配时间的延长,马氏体或马-奥组织的微观形貌会发生变化;分配时间较短的试样综合力学性能更好,在淬火终点温度为250℃,分配时间为60 s时得到的试样强塑积最高,可达22238 MPa·%;试样的拉伸断口显示出良好的韧性断裂特征;在Q&P处理后试验钢的残留奥氏体含量大幅提高。

TSCR工艺制备600MPa级TRIP钢的组织与力学性能

在实验室条件下模拟薄板坯连铸连轧工艺试制了600MPa级C-Si-Mn系TRIP钢,拉伸实验检测表明,试验钢的力学性能为σb=630MPa,σs=460MPa,δ=29.1%;组织观察发现,试样组织为铁素体+贝氏体+残余奥氏体,彩色金相定量分析结果表明残余奥氏体的体积分数为6.6%。

TRIP钢热变形后冷却工艺的优化

采用正交实验的方法在热模拟机上进行了TRIP钢热变形后冷却工艺的优化研究。结果表明,热变形后控制铁素体相变的慢速冷却的速度及控制贝氏体相变的快速冷却的速度对最终组织的组成影响较大;在分析实验数据的基础上,提出了TRIP钢轧后最佳冷却工艺。

汽车用高强度TRIP钢组织性能及成形工艺

概述了高强度TRIP钢对汽车轻量化的作用及TRIP钢的显微组织对其性能的影响,探讨了铁素体、贝氏体、残余奥氏体的含量对TRIP钢性能的影响规律,以及设备、模具和成形工艺参数的选择原则。结果表明,TRIP钢中铁素体可以提高钢的塑性,贝氏体可以提高强度和韧性,而当残余奥氏体的体积分数大于8%时,产生TRIP效应,并提高了钢的综合性能;以上组织的获得,应在成形时控制成形设备的能量、载荷、速度、时间等工艺参数。

将淬火—碳分配—回火(Q-P-T)及塑性成形一体化技术用于TRIP钢的创议

为改善环保,节约能源和原材料,降低车辆重量,亟需提高用于汽车件的TRIP钢强度。应用淬火—碳分配—回火(Q-P-T)工艺代替TRIP的一般热处理工艺,钢的抗拉强度已能高达2000MPa以上,断后伸长率在10%以上,但不能保证具有足够的残留奥氏体量。为此创议将Q-P-T工艺及塑性成形一体化技术用于TRIP钢,其精选工艺根据应力作用下的相变原理制定,既能达到显著提高的力学性质,如抗拉强度1500～2000MPa,断后伸长率10%～15%,适量的残留奥氏体,如约12%,还能进一步节能和改善环保。

C-Si-Mn系TRIP钢热变形后冷却工艺优化研究

采用正交实验的方法在热模拟机上对C-Si-Mn系TRIP钢热变形后的冷却工艺进行了优化研究,结果表明热变形后控制铁素体相变的慢速冷却速度及控制贝氏体相变的快速冷却速度对最终组织的组成影响大;在分析实验数据基础上,提出了C-Si-Mn系TRIP钢轧后冷却优化工艺原则.

贝氏体区等温处理对超高强度TRIP钢组织及力学性能的影响

利用金相显微镜、EBSD技术、x射线衍射仪等研究了C—Si—Mn系冷轧TRIP铜贝氏体区等温处理对组织和力学性能的影响，并尝试利用间接方法控制TRIP钢中的相组成。结果表明，残余奥氏体直径在2～3um之间，以椭圆状和细条状分布在铁素体晶界及晶内。随贝氏体区保温时间的延长，残余奥氏体体积分数先增大后减少，残余奥氏体中碳含量增多；随贝氏体区等温温度的升高，残余奥氏体体积分数达到峰值所需时间减少，峰值减小。相同等温时间下，等温温度越高，残余奥氏体中的碳含量越大。残余奥氏体的体积分数及其碳含量综合影响TRIP钢的力学性能。