Effects of Magnetic Field Intensity on Carbon Diffusion in Pure Iron in Paramagnetic Ferrite Region

Effects of magnetic field intensity on carbon diffusion in pure iron in paramagnetic ferrite region above the Curie temperature were investigated using carburizing technology. It was found that the magnetic field intensity can significantly affect the carbon diffusion behavior in pure iron in paramagnetic ferrite region in the direction parallel to the magnetic field direction, both the carbon diffusion coefficient and the average carbon diffusion distance increase gradually with the increasing of the magnetic field intensity. Magnetic field annealing obviously promotes the carbon diffusion in pure iron in the direction parallel to the magnetic field in paramagnetic ferrite region above the Curie temperature, and promotion effect increases with the enhancement of the magnetic field intensity. The structure defects made by the magnetic field may cause the increasing of carbon diffusion flux.

Study on Texture and Deep Drawability of Ti-IF Steel Sheets Hot-Rolled in Ferrite Region

The effect of hot rolling temperature and reduction in ferrite region on the microstructure, texture and deep drawability of Ti-IF steel sheets were investigated. The results showed that after ferritic hot rolling and annealing, Ti-IF steel sheets developed uniform equiaxed ferrite grains and strong <111>//ND recrystallized fibers, the maximum r-value was 1.725 and good deep drawability was achieved. The deep drawability was improved with the decrease of ferritic hot rolling temperature, also enhanced with the increase of reduction in ferrite region. Texture analysis indicated that low hot rolling temperature and large reduction in ferrite region could increase the intensities of favorable {111}<112> and {554}<225> recrystallization textures and also reduce that of unfavorable {001}<110> recrystallization texture, therefore the r-value and deep drawability were enhanced.

Recrystallization Behavior Immediately after Hot-Rolling in Ferrite Region in Ultra Low Carbon Sheet Steels

One-pass hot rolling in the ferrite region was conducted at higher temperatures, using various rolling temperatures and rolling reductions, with two types of ULC steels, 0.016% Nb and 0.023% Ti, and recrystallization behaviors immediately after hot rolling were investigated. The γ-fiber strength reached its maximum at around 50% rolling reduction at 1273K with the Nb-added steel and 1323K with the Ti-added steel. On the other hand, in high temperature rolling of the Ti-added steel, the γ-fiber did not develop, independent of rolling reduction. These changes corresponded to the recrystallized fraction, in that the strength of the γ-fiber decreased when recrystallization occurred immediately after rolling. New recrystallized-like grains were produced in the domain where distortions were particularly concentrated. Recrystallization seemed to be the result of various mechanisms, as some recrystallized grains were formed by a bulging mechanism, whilst others were surrounded by high angle grain boundaries.

Resistance Matrix of Micro-Carbon Steel Rolled in Ferrite Region

This paper is written to discuss the Gleeble simulation experiment of micro-carbon steel rolled in ferrite region. By measuring the resistances under different rolling temperatures, rolling speeds and rolling deformation, the matrix of micro-carbon steel is established, after that, the matrix is also regressed and the result proves that the accordance of the matrix is good. This show the matrix established can be used to calculate the rolling parameters of micro-carbon steel.