Papers by Keyword: Cold Rolled

Abstract: Aluminium 8011 cast plates subjected to cold rolling to reduce thickness from 12 mm to 3.5 sheets. As rolled aluminium sheet was subjected to annealing treatment after rolling. This work deals with the study of planar and normal anisotropy parameters of as rolled aluminium and rolled with annealed aluminium sheets. The tensile test samples were cut at 0°, 30°, 45°, 60° and 90° with respect to the rolling direction of as rolled Al sheet and rolled with annealed Al sheet. Tensile properties were measured at different orientations to the rolling directions. The wide variation in tensile strength was found in case of as rolled Al samples at different orientation to rolling direction of sheet (208 to 243 MPa). On the other hand nearly uniform tensile strength (128 MPa to 132 MPa) was measured for rolled and annealed Al samples at different orientations. As rolled Al samples shows anisotropic tensile properties where as isotropic tensile properties were measured for rolled with annealed Al samples. Al grains are more elongated along the rolling directions where as rolled and annealed Al sample shows more equiaxed grains which is attributed to isotropic behaviour of Al sheets. The normal anisotropy parameter or average r_m value is higher (1.24) in case of rolled and annealed sheet sample as compared to as rolled Al sheet r_m value (1.06). This is attributed to isotropic behaviour of rolled and annealed samples. Toughness and ductility properties are improved more than 3 times in case of rolled and annealed Al sheet samples. Annealing treatment of rolled Al sheet samples shows elongated grain morphology changes to equiaxed grains of aluminum which tends to improved formability and isotropic mechanical properties Al sheet. For determination of normal anisotropy (r_m) value, tensile results R values are required at angles of 0 degrees, 45 degrees, and 90 degrees. However in this study additional R values are estimated at 30 degree and 60 degree in order to understand trend of R value at every 30 degree from 0 to 90 degree.

Abstract: The precipitating behavior of δ phase in GH4169G alloy at 910°C was investigated and a novel process for achieving fine-grained GH4169G sheet with average grain size of ASTM13 was proposed. Globular δ phase precipitation precedes that of the plate-like δ phase, forming at grain boundary first and later in grain. After globular δ phase reaches a peak volume, it begins to transform into plate-like in grain boundary, and then the plate-like δ phase forms in grain in certain direction. The grain-fined process includes the following steps:(1) solution treated at a proper temperature, then air cooled; (2) soaked for δ phase precipitation; (3) cold rolled; (4) annealed for recrystallization. Microstructure analysis from optical microscopy (OM) and scanning electron microscopy (SEM) revealed that both plate-like and globular δ phase remarkably restrained the grain growth during annealing recrystallization. The optimum parameters for the grain refinement were determined finally.

Abstract: According to thermodynamics of materials, selection of microalloying composition for developing cold rolled structural steel sheet with different strength levels was investigated, by comparing and analyzing the solid solubility and lattice constant of microalloying elements V, Nb and Ti, ideal microalloying composition-niobium and titanium compound additives was obtained, and then process parameters including reheating temperature and annealing process were discussed.

Abstract: The 4.2wt.%Si non-oriented electrical steel thin sheets with the thickness of 0.30mm were produced by the conventional procedure including hot rolling, cold rolling and annealing. The recrystallization texture was analyzed with emphasis on the effect of normalizing annealing. The results show that the  fiber with peak at {111} is weaker and η fiber is stronger in the sheets with normalizing annealing than those without normalizing annealing, either under the cold rolled reduction of 77% or 86%. Effects of normalizing annealing on the recrystallization texture can be explained in terms of the characteristic of the shear bands formed during cold rolling process.

Abstract: Under laboratory conditions, simulated Bell-type annealing technology , researched the annealing temperature on the SPCC cold-rolled steel sheet mechanical properties. The results indicate that when the time of annealing is shorter (1h), the hardness of steel that used to test decreased with the annealing temperature increased; when the time of annealing is longer (5h), the microhardness is increase slightly with the annealing temperature increased, while the lower plastic decreased.

Abstract: 0.2mm-thick high silicon steel thin sheet under 94% cold rolling reductions has been successfully produced by conventional rolling method. Texture evolution during hot rolling, cold rolling and final annealing as well as magnetic properties has been investigated with emphasis on the effect of finishing temperature. It is found that a favorable strong {001}<210> recrystallization texture and evidently improved magnetic properties can be obtained at the finishing temperature of 900°C, which is in contrast with relatively strong detrimental {111}<112> and weak {001}<210> recrystallization texture at the finishing temperature of 700°C. Effects of finishing temperature can be explained in terms of the cold rolling texture due to different texture morphology in hot bands.

Abstract: In this paper, the effect of soaking temperature during continuous annealing on mechanical property of high-tensile cold rolled bake-hardening steel was studied by using hot-dip process simulator. The results show that it can finish re-crystallization process when the soaking temperature increased from 740°C to 850°C. As the temperature increased, the yield strength, tension strength and microhardness monotone decreased and the n value monotone increased by contrast. At the same time, the total elongation and r value of BH steel increased at the beginning and decreased later, they would all reached a peak value at about 820°C.

Abstract: The cold-rolled production line of double-line continuous electrolytic pickling is quite common in the manufacture of all kinds of small-diameter cold-rolled thread steel. This paper studies the main technology parameters, the main device with the structure characteristics and the principle of the cold-rolled production line of double-line continuous electrolytic pickling, and then analyzes on the experiments and on the technological economics for the small-diameter cold-rolled thread steel. The results show that its production line is convenient in operation, accurate in processing, efficient and adaptable in production. The small-diameter cold-rolled thread steel produced by this production line has high strength, large plasticity and good yield performance and bending characteristics. It can greatly improve the performance of reinforced concrete structure and prestress reinforced concrete structure, increases the quality of components, and saves steel about 15%. So it is a high efficiency, energy-saving steel. Small-diameter cold-rolled thread steel is widely used in the construction industry with very significant economic and social benefits, it plays an important role to accelerate the economic construction of China.

Abstract: CuFe10 and CuFe15 (mass fraction) alloys were prepared by vacuum induction melting and were cold rolled heavily at room temperature. Microstructure, microhardness and electrical conductivity of these alloys were measured at various cold rolled strain levels. The experimental results showed that the microhardness increased rapidly and the electrical conductivity decreases gradually with the increase of rolling strain at first. The microhardness increased slowly while the strain η greater than 2.3. The Fe-rich phases are deformed to ribbons filaments. However, the electrical conductivity increases again after deforming to a certain degree. The final electrical conductivities of heavily cold rolled CuFe10 and CuFe15 alloys were slight lower than vacuum inducing melted master alloys, however, the microhardness had increased about 44% and 47%, respectively.

Abstract: Small amounts of Mn have been used in order to modify the microstructure and thus improve the properties of the alloys. The effect of Mn addition on structure and properties of cold rolled Al-Mg-Si-Cu alloy at different annealed temperatures is presented in this paper. Both recrystallization temperature and activation energy of recrystallization are obtained from the hardness-temperature curves. The results show that Mn can have an inhibitive effect on recrystallization. Within a certain concentration of Mn in the alloy (<0.7 wt.%) both the activation energy of recrystallization and recrystallization start temperature increase with the addition of Mn content. The activation energy of recrystallization of the alloy which contains 0 wt.% Mn, 0.3 wt.% Mn and 0.7 wt.% Mn are respectively 134.4 kJ·mol-1, 137.4 kJ·mol-1 and 140.1 kJ·mol-1 and the recrystallization start temperature increases from 190 to 230 as Mn content increases from 0 to 0.7 wt.%.