Research on the Digital Transformation of the Whole Industry Chain of Guangdong Supply and Marketing Cooperative

Guangdong Supply and Marketing Cooperative serves as an important institution for the“Three Rural Areas”in the Guangdong-Hong Kong-Macao Greater Bay Area.Its digital transformation and optimization serve as powerful supports for rural revitalization.This paper systematically reviews the main practices and effectiveness of the digital transformation within the Guangdong Supply and Marketing Cooperative.It also analyzes the current development dilemmas faced in the construction of digital supply and marketing.Additionally,it proposes targeted solutions,including building a big data resource base,optimizing the digital supply and marketing cloud platform,developing digital publictype agricultural social service applications,establishing a new model of rural e-commerce,enhancing the traceability management system for agricultural products,and strengthening the construction of the digital human resources system.These proposals aim to further promote the strategy for revitalizing the countryside.

Quantifying China's iron and steel industry's CO_(2) emissions and environmental health burdens:A pathway to sustainable transformation

Assessing the iron and steel industry's(ISI)impact on climate change and environmental health is vital,particularly in China,where this sector significantly influences air quality and CO_(2)emissions.There is a lack of comprehensive analyses that consider the environmental and health burdens of manufacturing processes for ISI enterprises.Here,we present an integrated emission inventory that encompasses air pollutants and CO_(2)emissions from 811 ISI enterprises and five key manufacturing processes in 2020.Our analysis shows that sintering is the primary source of air pollution in the ISI.It contributes 71%of SO_(2),73%of NO_(x),and 54%of PM_(2.5)emissions.On the other hand,81%of total CO_(2)emissions come from blast furnaces.Significantly,the contributions of ISI have resulted in an increase of 3.6 mg m^(-3)in national population-weighted PM_(2.5)concentration,causing approximately 59,035 premature deaths in 2020.Emissions from Hebei,Jiangsu,Shandong,Shanxi,and Inner Mongolia provinces contributed to 48%of PM_(2.5)-related deaths in China.Moreover,the transportation of air pollutants across provincial borders highlights a concerning trend of environmental health inequality.Based on the research findings,it is crucial for ISI manufacturers to prioritize the removal of outdated production capacities and adopt energy-efficient and advanced techniques,along with ultra-low emission technologies.This is particularly important for those manufacturers with substantial environmental footprints.These transformative actions are essential in mitigating the environmental and health impacts in the affected regions.

Research on the Digital Economy,Technological Innovation,and Transformation and Upgrading of the Manufacturing Industry in Shandong Province

Based on panel data from 16 cities in Shandong Province from 2013 to 2022,and grounded in theoretical analysis,this paper constructs a benchmark regression model,a mediating effect model,and a heterogeneity test for empirical analysis.The results show that:(1)the digital economy has a significant positive effect on promoting the transformation and upgrading of the manufacturing industry in Shandong Province;(2)the digital economy can drive the transformation and upgrading of the manufacturing industry through technological innovation;and(3)the impact of the digital economy on the transformation and upgrading of the manufacturing industry in Shandong Province is evidently heterogeneous.

Kinetics of austenite growth and bainite transformation during reheating and cooling treatments of high strength microalloyed steel produced by sub-rapid solidification

First,strip cast samples of high strength microalloyed steel with sub-rapid solidification characteristics were prepared by simulated strip casting technique.Next,the isothermal growth of austenite grain during the reheating treatment of strip casts was observed in situ through confocal laser scanning microscope(CLSM).The results indicated that the time exponent of grains growth suddenly rise when the isothermal temperature higher than 1000℃.And the activation energy for austenite grain growth were calculated to be 538.0 kJ/mol in the high temperature region(above 1000℃)and 693.2 kJ/mol in the low temperature region(below 1000℃),respectively.Then,the kinetics model of austenite isothermal growth was established,which can predict the austenite grain size during isothermal hold very well.Besides,high density of second phase particles with small size was found during the isothermal hold at the low temperature region,leading to the refinement of austenite grain.After isothermal hold at different temperature for 1800 s,the bainite transformation in microalloyed steel strip was also observed in situ during the continuous cooling process.And growth rates of bainite plates with different nucleation positions and different prior austenite grain size(PAGS)were calculated.It was indicated that the growth rate of the bainite plate is not only related to the nucleation position but also to the PAGS.

Effect of Chromium-enhanced Diffusivity on Reverted Transformation in Metastable Austenitic Stainless Steels:Theoretical Calculation and Experiment

Effects of nucleation sites and diffusivity enhancement of chromium on reverted transformation of AISI 304 stainless steel during annealing process were investigated.Dynamics calculation revealed that the reverted transformation of strain-inducedα’-martensite→γaustenite could were closely associated with active nucleation sites and diffusivity enhancement of chromium in nanocrystallineα’-martensite.The experimental data and the results were in accordance with 2-grain austenite/α’-martensite junctions calculated theoretically,which could result from high chromium diffusion rate in nanocrystallineα’-martensite.In addition,low temperature is not conducive to reversed transformation,while high temperature and long annealing time will lead to inhomogeneous grain size distribution.

Literature Review of Phase Transformations and Cavitation Erosion of Duplex Stainless Steels

Phase transformation is one of the factors that would significantly influence the ability to resist cavitation erosion of stainless steels. Due to the specific properties of duplex stainless steel, the heat treatment would bring about significant phase transformations. In this paper, we have examined the previous studies on the phase transition of stainless steel, including the literature on the classification of stainless steel, spinodal decomposition, sigma phase transformation, and cavitation erosion of double stainless steel. Through these literature investigations, the destruction of cavitation erosion on duplex stainless steel can be clearly known, and the causes of failure of duplex stainless steel in seawater can be clarified, thus providing a theoretical basis for subsequent scientific research. And the review is about to help assess the possibility of using bulk heat treatment to improve the cavitation erosion (CE) behaviour of the duplex stainless steel 7MoPLUS.

On the Digital Transformation of the Automobile Manufacturing Industry in the Chengdu-Chongqing Economic Circle:Mechanism of Action and Feasible Paths

With a long industrial chain and a powerful ability to drive other industries,the automobile manufacturing industry has a prominent strategic position in the national economy.In recent years,many countries have put on their agenda the digitalization of the automobile manufacturing industry,leading to an connected,autonomous,shared,and electric(also known as CASE)①development trend in the industry.As one of the six major automobile industry clusters in China,the Chengdu-Chongqing economic circle has achieved initial results in the digital transformation of the automobile manufacturing industry.However,the region is still faced with some constraints,such as insufficient digital infrastructure,relatively slow development of new automobile products,insufficient innovation ability of the automobile industry,and complex digital transformation of small and medium-sized automobile enterprises(automobile SMEs).This paper intends to construct a framework for the mechanism of action of the digital transformation in the automobile manufacturing industry,analyze the effects of the digital transformation of the automobile manufacturing industry in the Chengdu-Chongqing economic circle,and propose feasible paths for the digital transformation of the automobile manufacturing industry in the region by drawing on domestic and international experience in this regard.The specific paths include:(a)Smoothing the“dual-core”data chain to facilitate the digital transformation of the automobile manufacturing industry;(b)Developing the new energy vehicle(NEV)industry to upgrade the quality of automobile products;(c)Achieving corner overtaking in the digital transformation of the automobile manufacturing industry with digital technology;(d)Jointly building the automobile industrial park to promote the digital transformation of the industry;(e)Addressing problems facing automobile SMEs in digital transformation via targeted policy tools.

Eco-transformation of steel industry in China: from the perspective of industrial ecology and circular economy

Recently the behavior of human has resulted in the deterioration of global ecological environment, and global warming and environmental pollution have caused the occurrence of extreme events frequently If we repeat the reckless environmental overkill, civilization will enter a victous circle of decline and lose even the strength and vitality to live in harmony with the environment. At Present, China is in a speciat period of rapid economic develop- ment. Some enterprises focus on short-term profits and don＇t formulate long-term strategies. For example, with the rapid expansion of the steel industry, some serious problems have emerged. Based on principles of industrial ecology and the concept of circular economy, to develop a new development model, taking a new road to industrialization is very necessary. Re-examining the current steel enterprises, this＇ paper proposes the new methods of the integration of material, energy integration, water system integration and sharing of information and facilities. Through ecologi- calization of technology, system, and industrial structure and product structure adjustment, the eco-transformation of the modern steel industry will be gradually achieved in China

Effect of silicon and prior deformation of austenite on isothermal transformation in low carbon steels

Isothermal transformation （TTT） behavior of the low carbon steels with two Si contents （0.50 wt pct and 1.35 wt pct） was investigated with and without the prior deformation. The results show that Si and the prior deformation of the austenite have significant effects on the transformation of the ferrite and bainite. The addition of Si refines the ferrite grains, accelerates the polygonal ferrite transformation and the formation of M/A constituents, leading to the improvement of the strength. The ferrite grains formed under the prior deformation of the austenite become more homogeneous and refined. However, the influence of deformation on the tensile strength of both steels is dependent on the isothermal temperatures. Thermodynamic calculation indicates that Si and prior deformation reduce the incubation time of both ferrite and bainite transformation, but the effect is weakened by the decrease of the isothermal temperatures.

EFFECT OF SILICON ADDITION ON RECRYSTALLIZATION AND PHASE TRANSFORMATION BEHAVIOR OF HIGH-STRENGTH HOT-ROLLED TRIP STEEL

Because Si is a noncarbide forming element, a multiphase microstructure consisting of ferrite, bainite, and retained austenite, at room temperature, can be formed by controlling the thermomechanical process strictly. The cooling schedules must be restricted by the formation of pearlite and cementite. In the present article, a new integrated mathematical model for prediction of microstructure evolution during controlled rolling and controlled cooling is developed for a typical kind of low carbon Si-Mn TRIP steel, which consists of temperature simulation, recrystallization, and transformation models. The influence of Si contents has been thoroughly investigated. The calculated results indicate that Si retards recrystallization, restrains austenite grain growth as well as accelerates polygonal ferrite transformation.

Research on the Mechanism and Strategy of Equity Investment Driving the Transformation of New Material Innovation Achievements

Under the wave of global technological revolution,the new materials industry is facing difficulties in innovation and transformation.Equity investment has become a key driving force due to its flexible mechanism,risk sharing,and deep participation.Based on introducing the current development status of China’s new materials industry,this article reveals the mechanism of equity investment in financial support,risk management,incentive constraints,and resource integration.The article proposes optimization strategies,such as building an information-sharing mechanism and a diversified investment fund system,to promote the high-quality development of the new materials industry driven by innovation and provide strategic guidance for policymakers,investors,and enterprises.

Cogitation on the digital transformation of the process manufacturing industry triggered by the practices of the PIDAS

Digital transformation is the process of an industry moving to a digital business of continuous growth and improvement with digital technologies.It is an important path for the manufacturing industry to reconstruct and upgrade the existing operation mode to achieve efficiency, effectiveness, and product quality improvement.In this study, we analyze why the successful digital transformation practice is scarcely found in the core business of process manufacturing industries, such as the steel and cement industries.By introducing the development and application of the Process Intelligent Data Application System(PIDAS),which is the digital platform of heavy plates in Baosteel, the concepts, ideas, and development experience of the digital transformation of the process manufacturing are summarized.Moreover, the core issues worthy of attention are pointed out.Finally, a feasible route for the digital transformation of the process manufacturing is proposed.

Investigation into the stress-strain curves of deformation-induced ferrite transformation in a low carbon steel

A series of tests of deformation-induced ferrite transformation （DIP-T） in a low carbon steel were carried out by the Gleeble-3500 hot simulation machine at a temperature range of Ae3-Ar3. The overall stress-strain curves during DIFT can be divided into three typical types： ＂double-humped＂,＂ single-humped＂ and ＂transitional＂. The peaks exhibited in the curve are involved with deformation-induced transformation which happened in grains or at the grain boundaries. According to the stress-time curve and strain-time curve, strain capacity dramatically postponed the strain-induced transformation, which leads to the start of the transformation right ahead of the finish of deformation and the majority of the ferrite transformation process mainly happened after the deformation. Deformation-induced transformation is a metadynamic transformation process with dynamic nucleation.

New Industrialization Path： The Strategic Choice of Chinese Iron and Steel Industry

The fact-developing iron and steel industry provides the base for China economy to grow continually, stably and healthily for many years. This paper analyzes the situation and the disparity, which the iron and steel industry faces, and attests that the new industrialization path is the strategic choice for the Chinese iron and steel industry to develop continuously, and carries on the thorough discussion to the connotation of this choice.

Solution of an Inverse Problem of Heat Conduction of 45 Steel with Martensite Phase Transformation in High Pressure during Gas Quenching

In order to simulate thermal strains, thermal stresses, residual stresses and microstructure of the steel during gas quenching by means of the numerical method, it is necessary to obtain an accurate boundary condition of temperature field. The surface heat transfer coefficient is a key parameter. The explicit finite difference method, nonlinear estimation method and the experimental relation between temperature and time during gas quenching have been used to solve the inverse problem of heat conduction. The relationship between surface temperature and surface heat transfer coefficient of a cylinder has been given. The nonlinear surface heat transfer coefficients include the coupled effects between martensitic phase transformation and temperature.

Kinetics of bainite-to-austenite transformation during continuous reheating in low carbon microalloyed steel

A dilatometer was used to study the kinetics of bainite-to-austenite transformation in low carbon microalloyed steel with the initial microstructure of bainite during the continuous reheating process. The bainite-to-austenite trans- formation was observed to take place in two steps at low heating rate. The first step is the dissolution of bainite, and the second one is the remaining bainite-to-austenite transformation controlled by a dissolution process. The calculation result of the kinetics of austenite formation shows that the two steps occur by diffusion at low heating rate. However, at high heating rate the bainite-to-austenite transformation occurs in a single step, and the process is mainly dominated by shear. The growth rate of austenite reaches the maximum at about 835℃ at different heating rates and the growth rate of austenite as a function of temperature increases with the increase in heating rate.

MECHANICAL STABILIZATION OF DEFORMED AUSTENITEDURING CONTINUOUS COOLING TRANSFORMATION IN AC-Mn-Cr-Ni-Mo PLASTIC DIE STEEL

The influence of prior austenite deformed at different temperature on the subsequent continuous cooling bainitic transformation has been investigated in an C-Ma-Cr-Ni-Mo plastic die steel. The results show that the prior deformation in low temperature region of austenite retards significantly the bainitic transformation. For the same continuous cooling schedule, as austenite deformed at lower temperature, the quantity of the classical sheaf-like bainite becomes less. The present results show that severe deformation leads to mechanical stabilization of austenite and causes the difficulty of bainitic ferrite propagation into the austenite.

Effect of V and V-N Microalloying on Deformation-Induced Ferrite Transformation in Low Carbon Steels

Deformation-induced ferrite transformation （DIFT） has been proved to be an effective approach to refine ferrite grains. This paper shows that the ferrite grains can further be refined through combination of DIFT and V or V-N microalloying. Vanadium dissolved in γ matrix restrains DIFT. During deformation, vanadium carbonitrides rapidly precipitate due to strain-induced precipitation, which causes decrease in vanadium dissolved in matrix and indirectly accelerates DIFT. Under heavy deformation, deformation induced ferrite （DIF） grains in V microalloyed steel were finer than those in V free steel. The more V added to steel, the finer DIF grains obtained. Moreover, the addition of N to V microalloyed steels can remarkably accelerate precipitation of V, and then promote DIFT. However, DIF grains in V-N microalloyed steel easily coarsen.

DEFORMATION ENHANCED FERRITE TRANSFORMATION IN PLAIN LOW CARBON STEEL

The microstructure evolution during deformation enhanced transformation of undercooled austenite of a plain low carbon steel has been investigated by means of hot compression simulation experiment under various conditions of strain rate, deformation temperature and strain. The effect of austenite grain size on the strain enhanced ferrite transformation has been studied. The ferrite dynamic recrystallization involved in successive hot deformation has been explored.

Martensite transformation induced by deformation and its phase electrochemical behavior for stainless steels AISI 304 and 316L

The martensite transformation induced by tensile elongation and its effect onthe behavior of phase electrochemistry of AISI 304 and 316L in 3.5% NaCl solution were studied. Theresults show that the content of α′-martensite in stainless steel 304 increases with the truestrain. As α′-martensite content increased, free corrosion potential and pitting potential ofstainless steel 304 in 3.5% NaCl solution appeared the change trend of a minimum. It was also foundthat pitting nucleated preferentially at the phase interfaces between martensite and austenite.There existed apparent difference between electrochemical properties of austenite and of martensitefor stainless steel 304 and 316L in 3.5% NaCl solution.