Parikin

Texture Analysis using The Neutron Diffraction Method on The Non Standardized Austenitic Steel Process by Machining,Annealing, and Rolling

Austenitic steel is one type of stainless steel whi ch is widely used in the industry. Many studies on austenitic stainless steel have been performed to determine the physical properties using various types of equipment and me thods. In this study, the neutron diffraction method is used to ch aracterize the materials which have been made from minerals extracted from the mines in Indonesia. The materials consist of a granular ferro-scrap, nickel, ferro-chrome, fe rro-manganese, and ferro-silicon added with a little titanium. Charact erization of the materials was carried out in three processes, namely: machining, annealing, and rolling. Experimental res ults obtained from the machining process generally produces a texture in the 〈100〉 direction. From the machining to annealing process , the texture index decreases from 3.0164 to 2.434. Texture strength in the machining process (BA2N sample) is 8.13 mrd and it then decreases to 6.99 in the annea li g process (A2DO sample). In the annealing process the three-c omponent texture appears, cube-on-edge type texture {110}〈001〉, cube-type texture {001} 〈100〉, and brass-type {110} 〈112〉. The texture is very strong leading to the directi on of orientation {100} 〈001〉, while the {011}〈100〉 is weaker than that of the {001}, and texture with orientation {110}〈112〉 is weak. In the annealing process stress release occurred, and this was shown by more randomly pole compared to st res release by the machining process. In the rolling process a bra ss-type texture{110} 〈112〉 with a spread towards the goss-type texture {110} 〈001〉 appeared, and the brass component is markedly rein fo ced compared to the undeformed state (before rolling). Moreover, the presence of an additional { 110} component was observed at the center of the (1 10) pole figure. The pole density of three components increases with the increasing degree of thickness reduction. By i ncreasing degrees of rolling from 81% to 87%, the value of orientatio n distribution function increases by a factor about three times.

Efek Rol Panas Pada Sifat Mekanik Plat Baja 15%cr-25%ni Bahan Struktur Reaktor

HOT-ROLLING EFFECTS ON MECHANICAL PROPERTIES OF 15%Cr-25%Ni STEEL PLATES FOR REACTOR STRUCTURE MATERIALS. The measurements of hot rolling effects on the mechanical properties of 15%Cr-25%Ni steel plates have been carried out to determine the formability of the materials. The specimens were prepared in the dimension of 50x20x7 mm3 to facilitate obtaining the measurement data. The results show that hot rolling was able to deform the grain size of 15%Cr-25%Ni steel plates to a smaller size, from 6 μm round into 4 μm (longitudinal) and 3 μm (transversal) lengthening bands after hot-roll reduction of 70%. The hardness of 15%Cr-25%Ni steel plates increased by 27%, from 100.02 HVN before hot rolling to 126.86 HVN after hot-rolling reduction of 70%. The improvement in hardness is predominantly caused by strain hardening and grain refinements, instead of by CrxCy inclusion effects. The hardness increase was probably caused by crystal volume shrinkage of 0.35%, i.e. the rolled lattice parameter was smaller than unrolled specimen (initial). The shrinkage is identifiable from the shifted diffraction peaks of (311) and (222) around diffraction angles of 2θ=91° dan 96° respectively. In cold rolling which was, unlike hot rolling, carried out below the recrystallization temperature, there was no phase transformation due to hot rolling process. All of the 15%Cr-25%Ni steel was a face centered cubic (fcc) with space group of Fm3m and the lattice parameter α= 3.58 A. Hot rolling effects caused strong crystal orientaion in {110} texture Brass components with broadening in {011} texture Goss components, while prior to the rolling the dominant orientation was the {001} cubic component.