Light and electron microscopic observation of malignant gastric leiomyoblastoma

There were only a few cases of gastric leiomy-oblastoma reported in domestic literature,while themalignant ones were even more seldom.One ofthese was diagnosed by gastroscopic biopsy with lightand electron microscopy in our department in 1988.CASE REPORTA 57-yeat old- male worker,suffered from re-current dull pain over the upper abdomen for 2

Effect of Annealing Temperature on the Precipitation Behavior and Texture Evolution in a Warm-Rolled P-Containing Interstitial-Free High Strength Steel

By using transmission electron microscopy and electron back-scattered diffraction, the effect of annealing temperature on the precipitation behavior and texture evolution in a warm-rolled interstitial-free high strength steel was studied. The results indicated that fine FeTiP could precipitate at 650 ℃, and the number of those precipitates increased greatly with the increasing annealing temperature until 800 ℃. Furthermore, the nucleation of FeTiP was influenced by the precipitation of TiC and （Ti, Nb） C. The near absence of FeTiP and a large volume fraction of TiC and （Ti, Nb） C in matrix are envisaged to be primarily responsible for the sharp y-fiber texture. As the boundary pinning effect caused by FeTiP is weak and there are less interstitial C atoms in matrix. Thus, annealing at 800 ℃ leads to the highest intensity of y-fiber texture.

Composition and processing of direct-quench hot rolled steels with ultrahigh strength exceeding GPa

The design of high-strength steel has long been discussed in the field of metal structural materials.To further increase the strength of common high-strength steel and further decrease the cost for production,three direct-quench hot rolled steels were designed and fabricated.The rolling and coiling processes were set based on continuous cooling transformation curves.In addition,the effect of the coiling temperature on the tensile properties was discussed to further guide the optimization of the process.It was found that compared with granular bainite,lower bainite probably has more advantages for both the strength and low temperature impact toughness of direct-quench hot rolled steels.Through a process of tailoring the morphology of bainite and controlling the grain boundary precipitation,the newly designed direct-quench hot rolled steels showed greatly improved strength and acceptable ductility/toughness compared with traditional quenched and tempered steels.

Effect of Heat Treatment on Microstructures and Mechanical Properties of Hot-Dip Galvanized DP Steels

In order to simulate the hot-dipped galvanizing of dual-phase （DP） steel （wt%） 0.15C-0.1Si-1.7Mn, the DP steels were obtained by different annealing schedules. The effects of soaking temperature, time, and cooling rate on ferrite grain, volume fraction of martensite, and the fine structure of martensite were studied. Results showed that the yield strength （YS） of DP steel is sensitive to annealing schedule, while total elongation has no noticeable dependence on annealing schedule. Increasing soaking temperature from 790 to 850 ℃, the YS is the lowest at soaking temperature of 850 ℃. Changing CR1 from 6 to 24 ℃/s, the YS is the highest when CR1 is 12 ℃/s. Increasing soaking time from 30 to 100 s, the YS is the lowest at soaking time of 100 s. Besides, it was found that sufficient movable dislocations within ferrite grains and high martensite volume fraction can eliminate yield point elongation, decrease the YS, and increase ultimate tensile strength. Through TEM observations, it was also found that increasing annealing temperature promotes austenite transformation into twin martensite, and increases volume fraction of martensite at sufficient cooling rate. With increasing the martensite volume fraction, the deformation substructure in the ferrite is well developed.

Texture Evolution in Ferritic Rolled Ti-IF Steel During Cold Rolling

The texture evolution of ferritic hot rolled Ti-IF steel during cold rolling was investigated in which the reduction was from 15% to 85 %. It was found that α fibre texture was monotonously intensified with the increase in the cold rolling reduction, while y fibre texture changed in a different way. When the cold rolling reduction was in the range of 15 % -- 35 % or 45 % -- 75 %, γ fibre texture was strengthened ; however, when the cold rolling reduction was 35 %- 45 % or 75 %- 85%, the intensity of 7 fibre was reduced. The 7 fibre displayed a maximum intensity for the reduction of 75%, and the highest average plastic strain ratio was simultaneously obtained owing to the favorable recrystallization texture.

Industrial Atmospheric Corrosion Resistance of P-RE Weathering Steel

The corrosion behavior of low carbon steel （CS）, P-bearing steel （PS） and P-RE weathering steel （P-REWS） exposed for two years in Jiangjin of China was investigated. The results showed that during 2-year exposure test, corrosion data of the experimental steels followed the bilogarithmic equation, and the average corrosion depth of PS and P-REWS was decreased by 19.5% and 28.2% respectively compared with that of CS. Scanning electron microscope, electrochemical impedance spectroscope and Fourier transform infrared spectroscope were used to characterize the corrosion products. The research results showed that P in steel could promote the formation of an amorphous ferric oxyhydroxide layer near the substrate. The addition of RE could effectively increase the charge transportation re sistanee of rust.

Effect of Nd2O3 doping on the electrical properties of Ba0.96Ca0.04Ti0.90Sn0.10O3 ceramics

The Ba（0.96）Ca（0.04）Ti（0.90）Sn（0.10）O3-xNd2 O3（x = 0-0.08%） ceramics were prepared via traditional solid-state sintering method. The influences of Nd3＋ substitution on the phase structure, dielectric properties,piezoelectric and ferroelectric properties of the ceramics were investigated. All the samples possess pure BaTiO3-type perovskite structure. MPB with orthorhombic and tetragonal phase coexist at around x = 0.03-0.04. Nd^（3＋） doping decreases both Tc and T（O-T） to lower temperature. All the samples exhibit an intermediate state with the coexistence of ferroelectric and diffuse relaxor ferroelectric behavior with the addition of Nd^（3＋）. The electric properties of the ceramics were optimized at x = 0.03 with d33, Kp, εr and Pr values of 545 pC/N, 51.9%, 24,412 and 10.74 μC/cm^2.