SS400钢化学成分与力学性能关系的回归分析

鞍钢宽厚板厂在SS400钢板的实际生产中，存在着钢板性能合格率低的问题。针对过去生产的SS400钢板，探讨了钢的化学成分对钢板屈服强度、抗拉强度及延伸率的影响，得出影响三者的显著因素为含碳量和钢板厚度。并将钢板的化学成分与力学性能进行线性回归分析，确定了用化学成分预测钢板力学性能指标的定量关系，可用于实际生产的指导。     

Φ60系列热轧成品钢管的开发

论述了热轧成品管的技术要求，工艺设计和产品开发，提出在工艺过程中消除缺陷应采取的措施。     

Influence of Controlled Rolling and Cooling Process on the Mechanical Properties of Low Carbon Cold Forging Steel

In the present paper,controlled rolling and cooling processing was conducted by using a laboratory hot rolling mill.The influence of different processing parameters on the mechanical properties of low carbon cold forging steel was investigated.The results show that the faster cooling after the deformation (especially in low temperature rolling conditions) leads to the refinement of the ferrite grain.The specimen exhibits very good mechanical properties owing to the finer ferrite grains.The pearlite morphologies can also affect the mechanical properties of low carbon cold forging steel.The mechanical properties increase with decreasing final cooling temperature within the range from 650℃ to 570 ℃ due to the finer interlamellar spacing of pearlite colony.The mechanical properties of the specimens with fast cooling after the conventional rolling are not only better than those of the specimens with slow cooling after low temperature rolling,but also almost similar to those of the specimens with fast cooling after low temperature rolling.It is suggested that fast cooling after high temperature rolling (the conventional rolling) process would be of important industrial value.     

冷轧总变形量、卷取温度对SPHC钢力学性能的影响

以CSP工艺在不同卷取温度下生产的SPHC冷轧基板为实验材料,采用不同的冷轧总变形量进行冷轧并退火。通过单向拉伸实验对不同工艺条件下的基本成形性能指标（r值、n值）和力学性能指标（屈服强度、抗拉强度、伸长率）进行测定。通过对比分析发现,当卷取温度为600℃、冷轧压下量为70％时,SPHC退火后会得到良好的力学性能和优异的冲压性能。     

Influence of the Speed of High-Carbon Steel Billet in the Patenting Unit on Its Final Structure and Mechanical Properties

Prestressed ferroconcrete structures are widely used at present. As a result, compressive stress is created in the concrete and tensile stress in the reinforcing rope. The stressed reinforcing rope is better able to withstand the external loads that it experiences throughout the life of the construction. Consequently, larger loads may be applied or, with unchanged load, the size of the construction may be decreased, with accompanying savings of concrete and steel. Today, it is important to develop a manufacturing technology for nanostructured reinforcing rope that may be used in prestressed concrete-steel constructions. This technology is based on patenting, in which the steel acquires the structure of a fine ferrite–carbide mixture characterized by high strength and improved deformability. In the present work, the influence of increased billet speed in the patenting unit on the final structure and mechanical properties of steel 80, 70, and 50 is investigated, with a view to increasing the productivity in patenting, without loss of strength or plasticity of the steel, in the production of blanks for nanostructured reinforcing rope that may be used in prestressed concrete-steel constructions. To determine the heat-treatment time and temperature, the Gleeble 3500 system is used to plot diagrams of the isothermal decomposition of undercooled austenite. In qualitative and quantitative analysis of the microstructure, the interlamellar spacing of the ferrite–carbide mixture is determined for different billet speeds in the patenting system. The mechanical properties are studied in tensile tests. It is found that, for all billet speeds, the interlamellar spacing of the ferrite–carbide mixture is practically the same and is optimal for subsequent drawing: 0.1–0.2 μm. Thanks to the fine structure of the ferrite–carbide mixture formed in patenting, the strength of the billet is increased. Hence, in subsequent drawing, the billet may withstand greater compression without fracture. In the production of patented billet for nanostructured reinforcing rope, its speed in the patenting unit may be increased to 5 m/min. Consequently, the productivity may be increased without loss of strength and plasticity of the billet.     

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The scale composition, mass percent and thickness of high carbon steel wire rod were investigated under different rolling and laying temperatures in order to improve the mechanical descaling property of high carbon steel wire rod. Effects of rolling and laying temperatures on scale properties were studied by using thermodynamics and kinetics of scale formation and growth. The works can provide technological supports for industrial practices. The requirement of customers is satisfied.     

化学成份对Cr16Ni6不锈钢力学性能的影响

通过对几年来（包括近期）生产的一部分Cr16Ni6的化学成份及对应的热处理制度下力学性能数据的收集汇总，着重从化学成份的角度研究了对其性能的影响，得出了C＋N及Ni的成份是影响Cr16Ni6性能的最关键因素，在正常的生产条件下，只要控制好化学成份，就能使Cr16Ni6获得理想的组织和性能。     

The Effect of Low Finish Rolling Temperatures on the Structure and Properties of an HSLA Steel

Abstract

A commercially produced HSLA steel was rolled at 980°C, 780°C and 660°C to study the effects of three different types of microstructure and texture on the tensile and impact properties of the product. The rolling reductions varied between 63 and 67%. The tensile and impact properties were measured in the longitudinal direction and compared with those of the original stock. Deformation at all three temperatures produced a textured product, although in the material deformed at 980°C it was very weak as partial recrystallisation had occurred prior to transformation. Rolling at 980°C and 780 °C produced little change in tensile properties although the microstructures in the two cases were very different. Rolling at 660°C produced a 66% increase in yield strength but with a loss in ductility. The impact toughness was improved in all three cases. After similar rolling reductions at 660°C the HSLA steel has a higher impact transition temperature than mild steel. This difference is partially attributable to the weaker {100}textural component in the HSLA steel.

Résumé

Un acier commercial HSLA a été laminé à 980°C, 780°C et 660°C pour étudier les effets de trios différents types de microstructure et de texture sur les caractéristiques de traction et d'impact de ce produit. Les pourcentages de réduction variaient entre 63 et 67%. Les propriétés en traction et à l'impact furent mesurées dans la direction longitudinale et comparées à celles du stock d'origine. Aux trois températures la déformation produisit une texture, faible toutefois dans le matériau déformé à 980°C puisqu'une recristallisation partielle avait eu lieu avant la transformation. Bien que les microstructures soient très différentes dans les deux cas, les laminages à 980°C et 780°C n'ont'introduit que de faibles changements aux caractéristiques de traction. Le laminage à 660°C produisit un accroissement de 66% de la limite d'écoulement mais avec une perte de ductilité. La ténacité fut améliorée dans les trois cas. Apres des réductions similaires lors du laminage à 660°C, l'acier HSLA a, pour l'impact, une temperature de transition plus élevée que celle de l'acier doux. Cette différence peut être partiellement attribuée à une composante de texture {100} plus faible dans l'acier HSLA.     

Relation between the Degree of Alloying,Structure, and Mechanical Properties of High-Strength Steel

Development of the ocean, especially in Arctic regions, calls for the construction of an up-to-date fleet, including nuclear-powered icebreakers, arctic vessels, gas carriers, fixed and floating drilling platforms, submarine systems for oil and gas extraction on the continental shelf, reinforcement of coastal regions, and the construction of ports. That will require large quantities of weldable low-temperature steels that are also of high strength, so as to minimize the mass of the structures. The Zvezda shipbuilding complex in the far east of Russia is intended to meet that need. It is the largest such facility not only in Russia but in the world. In addition, the Vyborg ship-building plant and the Northern Shipyard (Severnaya Verf) in St Petersburg are being modernized. Another important task is the creation of new steels with the least possible alloying and standardized composition, so as to permit the development of more economical welding and assembly technologies. In the present work, the structure formed in low-alloy steels with variable content during plastic deformation is discussed. Samples from three melts of different chemical composition are studied: specifically, the melts differ in nickel content: 0.5, 1, and 2% Ni. The steels are tested on the Gleeble 3800 research complex, which simulates thermomechanical treatment with different temperatures in the final stage of rolling and with accelerated cooling to the specified temperature. The structure is studied by optical metallography and crystallographic analysis using a scanning electron microscope (EBSD analysis). The mechanical properties of the steels are determined. The thermal and deformational treatment of the steel must be selected in accordance with their level of alloying—that is, with the final structure of the steel (ferrite–bainite, bainite, or martensite–bainite). It is found that, in steel with ferrite–bainite structure, the best approach to strengthening is to create small-angle boundaries in the α phase during plastic deformation. Steel with bainitic structure does not undergo marked strengthening as a result of change in the deformation temperature during the final stage of thermomechanical treatment. For martensite–bainite structure, no treatment ensures the creation of additional small-angle boundaries. That may be associated with subsequent polymorphic transformation by a shear mechanism.     

Q345轧制工艺温度对力学性能的影响

通过工业试验研究了精轧和冷却过程温度对力学性能的影响,通过力学性能试验结果研究了温度与力学性能的相关性。结果表明,在一定范围内,屈服强度、抗拉强度、伸长率和冲击功随温度的升高略有上升,当温度超过一定值时均下降。Q345B在精轧温度880~890℃、终轧温度820~830℃、终冷温度660~680℃的条件下,综合力学性能较好。     

终轧温度对09CuPTiRE耐腐蚀钢板组织和性能的影响

通过金相、电子探针观察和单向拉伸试验,对不同终轧温度的09CuPTiRE钢板的金相组织、夹杂物和力学性能进行了研究,结果表明:在一定范围内,随着终轧温度的增大,钢板组织的晶粒平均尺寸变小,低温横向冲击韧性得到一定程度的改善。稀土元素改善了硫化物形态,提高了钢板的低温横向冲击性能。济钢中板厂的现场设备条件完全能达到低温终轧的能力,使09CuPTiRE热轧钢板达到新铁标的要求。     

Mathematical Modelling on the Microstructure Evolution of X60 Line Pipe Steel during CSP Hot Rolling

 An integrated process modelling system for simulating the microstructure evolution of Nb-microalloyed HSLA steel produced in CSP hot rolling process has been developed on the basis of the microstructure simulation and mechanical properties prediction technology. Thermo-mechanical coupled finite element models for simulating hot strip rolling have been developed and the distribution of equivalent plastic strain through the thickness direction in the rolled material of CSP rolling was carried out. Thus the distribution of temperature, strain and strain rate through the thickness of the steel stocks, as well as the microstructure evolution during hot rolling of X60 line pipe steel strip have been investigated by using the developed integrated process modelling system. In addition the determination and optimization of controllable process parameters during CSP hot strip rolling for the Nb-microalloyed X60 line pipe steel have been implemented, and control strategies such as adopting larger pass reduction in the first stand, and arranging appropriate pass interval times and proper rolling speed, to reduce or eliminate mixed-grains microstructure of Nb microalloyed strip in CSP processing have been proposed.     

Effects of Thermomagnetic Treatment on Microstructure and Mechanical Properties of Rolling Bearing Steel

 The influence of thermo-magnetic treatment of rolling-bearing steel on some its metallurgical and mechanical properties was investigated. The heating and/or cooling processes of the sample occurred in a magnetic field having certain intensities. The XRD patterns of rolling-bearing steel sample exhibited a beneficial effect of the magnetic field on the structure, phase transformation and tension state. It was found an increased reliability of rolling tribomodel made from thermo-magnetic treated steel when it was subjected to the fatigue tests.     

Effect of Hot Rolling Practice on Microstructure and Mechanical Properties of Fire-Resistant Steel

Trials to develop a C-Mn-Mo-Nb type fire-resistant steel have been carried out by adopting recrystallization rolling (RCR) + air cooling (AC),two-stage rolling (TSR) + AC and RCR + water cooling (WC).Both RCR and TSR followed by AC resulted in polygonal ferrite (F) + pearlite (P) microstructure,while F + bainite (B) microstructure was formed by RCR + WC.The plates with F+P microstructure show tensile strengths ≥490MPa,while those with F+B exhibit tensile strengths ≥590MPa.All the plates show favorable low yield ratios ≤ 0.75,good charpy v-notch impact property >101J at 0℃ and satisfactory high temperature strength (≥2/3 of room temperature yield strength retained at 600℃).     

轧制工艺对Ti微合金化马氏体钢力学性能的影响

 通过采用扫描电镜、透射电镜、X射线衍射以及相分析等手段来观察组织的微观结构和对析出相的验证,研究轧制温度对轧态Ti微合金化马氏体钢强度的影响。研究结果表明,通过降低轧制温度可以明显提高含Ti马氏体钢的屈服强度,这主要是因为当轧制温度从1100℃降低到950℃过程中,形变诱导析出大量的TiC析出相,随着轧制温度的降低,析出相数量明显增加,并且平均尺寸也逐渐变小。马氏体中大量存在的1～20nm范围的析出相可以起到明显的析出强化作用。     

Ni含量对控轧控冷船舶用Nb-Ti微合金化NiCr钢组织和性能的影响

研究了0.31%Ni和0.88%Ni二种控轧控冷Nb-Ti微合金化NiCr钢的组织和性能。结果表明,船舶用钢控轧控冷获得粒状贝氏体、上贝氏体、针状铁素体、多边形铁素体及少量珠光体等组成的复合组织。控轧控冷造成铁素体晶粒尺寸细化,细小M-A岛增多。二种钢均获得较高的抗拉强度、屈服强度、伸长率和硬度,0.88Ni-0.32Cr钢性能优于0.31Ni-0.33Cr钢。船舶用钢-80℃试样纵向冲击功都在200J以上,0.88Ni-0.32Cr钢甚至超过了300J。该钢中最佳的Ni含量为0.88%Ni。由于控轧控冷造成了铁素体细晶强化、M-A岛复合强化、析出强化和位错强化,合金元素镍有效的提高了船舶钢的低温冲击韧性。     

卷取温度和冷轧压下率对CSP流程深冲板组织性能的影响

 以低碳钢为实验原料,采用不同卷取温度和冷轧压下率进行工业实验,研究了卷取温度和冷轧压下率对深冲板组织和性能的影响。结果表明,卷取温度为570 ℃和600 ℃时,深冲板的组织为饼形晶粒;卷取温度为660 ℃和680 ℃时,深冲板的组织为等轴晶粒;卷取温度为600 ℃时,深冲板的综合性能最佳。压下率在75%时深冲板的综合性能最佳,此时rm为183,Δr为056。