Advanced Materials Research Vols. 535-537

Abstract: The recrystallization behavior of the cold rolled 3%Si nonoriented electrical steel at different temperatures is investigated by OIM(Orientation Imaging Microscopy). The results show that the recrystallization process and texture of 3%Si nonoriented electrical steel at different temperatures are determinated by different recrystallization mechanisms. At low annealing temperatures, the formation of recrystallization texture in this specimen can be explained by the mechanism of oriented nucleation theory, but at higher annealing temperatures, the formation of recrystallization texture in this specimen can be explained by the mechanism of oriented growth theory, the twin nucleation mechanism may penetrate the whole recrystallization process.

Abstract: The formation of 111-112 and 111-110 recrystallization textures during annealing of cold rolled low carbon steels at low heating rate was investigated by electron backscatter diffraction (EBSD) and X-ray diffraction techniques. The orientation characteristics during recrystallization of this steel were determined, results show that there is a strong competition between the 111-112 component and the 111-110 component along the γ-fiber. The former was developed from the deformed matrix with the same orientation by means of subgrain coalescence at early stage of recrystallization, while the latter nucleated at the grain boundary areas of deformed grains with 111-112 or 112-110 orientations by means of preferred nucleation and evolved into stable recrystallization texture at later stage of recrystallization.

Abstract: In this paper, to investigate the effect of stabilizing heat treatment for decreasing intergrular corrosion in welded AISI 321 steel by SMAW, at first, it was solution heat treatment in 1050°C and 3 hours , then it was stabilizing heat treatment in various times and temperatures for creating more chrome carbides which could not be created in first stage. Results indicated that, by increasing the temperature of stabilized heat treatment, more titanium carbides dissolves, while time increasing causes more creation of titanium carbides, decreasing of chrome carbides, and finally leads to increase of intergrnular corrosion resistance.

Abstract: Roll wear model for Hot Strip Mill (HSM) was researched and the factors affect roll wear are analyzed. The simulation program was compiled by program visual C++ language and work roll wear was calculated according to the rolling schedule. Calculation results shows that roll wear like box shape. Strip width affects roll wear clearly. The strip length is one of the important issues which affect roll wear. Work roll wear of F7 top roll middle get to 280μm after a rolling schedule. Roll wear curve calculated by program were good agreement with the wear curve got by high-precision grinder. The results show that the roll wear model has high accuracy.

Abstract: Abstract：Through physico-chemical analysis of soil under the buried pipeline, the corrosion influence factor of different ions such as 、 、 and on X80 has been studied. The result shows that when the ions concentration of 、 、 increases, the corrosion rate of X80 steel also rises and then reaches the maximum. After that, the corrosion rate begins decreasing. While for the case of ions, the corrosion rate of X80 steel keeps increasing with the concentration increase. Through detail analyzing the corrosion mechanism of different negative ions on buried pipeline steel and studying the soil corrosion rules, we can provide theoretical basis for the corrosion preventing work, which is very important and meaningful.

Abstract: The variations of T[O] and [N] as well as non metallic inclusions in different working processes of two kinds of SS400 steel production process in Han Group are studied systematically by tracing experiment, systematic sampling and integrated analyzing. The following results are observed: slag washing process and traditional process can both produce qualified steel. The slag washing process has good removal effect for Al2O3 inclusion compared with the traditional process. After slag washing treatment，the content of T[O] and [N] in slab when steady-state casting are respectively 21.75×10-6 and 24.9×10-6, which are respectively 84.9% and 76.1% of the content after LF treatment. The number of the micro inclusions is 5.583 piece/mm2,which is 79.2% of the number after LF treatment.

Abstract: Traditional IF steel is Ti-IF steel for low cost. Some car producer require IF steel to have good mechanical properties with low delta r (plastic stain ratio) value (△r) as well as high performance after welding. A new IF steel was developed by adjusting amount of Nb and Ti based on Ti-IF steel and employing suitable parameters in manufacturing processes. Annealing experiments were made to decide reasonable annealing temperature. The final products exhibit good isotropy with △r ≤0.3. This new type IF steel also had good performances after welding by analyzing results of some key parameters, which can totally meet requirement of car producer.

Abstract: Through comparative analysis of 3.5Ni low temperature steel with appending Ti and Nb elements, the effect on the structure and performance of steel plate rolling state, normalizing state and tempering state was studied. The results showed that the mechanical strength was increased and the low temperature ductility was improved for 3.5Ni low temperature steel with appending Ti and Nb elements; the normalizing process evidently decreased the temperature of transition microstructure.

Abstract: The homogeneous mixture of iron tailings powder and glass powder is as the experimental material to sinter the amorphous based material. The particle size of the glass powder is less than 0.15 millimeter, and the particle size of the iron tailings powder is from 0.07 millimeter to 2 millimeter. The weight percentages of glass powder are 10% and 15% and 22% and 25% in the experimental material, respectively. The heating rate is about 170°C•min-1 and the maximum sintering temperature is 1150°C.They are proved by the analysis results of thermo-gravimetric analysis and differential thermal analysis with the experimental material. And the sintering temperature and the heating rate of the sintering experiments were based on them. The facts that the sintered material is mostly made up of amorphous substance and contains a certain amount of crystals and it’s micromechanism is amorphous are proved out by the experiments of scanning electron microscope. The testing results of the sintered material are these that the maximum density is 2.6g.cm-1, the maximum compressive strength is 94MPa, the maximum tensile strength is 5MPa, the maximum bending strength is 28MPa, the hydroscopicity and the radioactivity is zero, and it can not be eroded by acids and alkalis. When the sintered material contains 22% glass powder, the mechanical properties of the sintered material sample is same as marble.

Abstract: Composite filler（1-x%）BNi-2+ x% BNi-5 with 3 different B content was used to braze 316L stainless steel. The boride near brazing seam was determined by energy spectrum, XRD Micro- area scanning and thermodynamics, dynamics calculation software THERMO –CALC to study the impacts of B content on boride type and quantity. The results showed Cr5B3 and Cr2B were found at and around brazing seam of 1# specimen and Cr2B were found at and around both 6# and 8# specimens. In addition, the Cr2B content of 6 # specimen was greater than 8 # specimen. With the increase of BNi-5 content and decrease of B in the brazing filler, the type and content of the chromium boride reduced.