Influence Of Solution Treatment Research Articles

Microstructure and mechanical properties of stainless steel produced by centrifugal-SHS process

The microstructure and mechanical properties of the stainless steel layer of a composite pipe produced by the centrifugal-SHS process were investigated. The possibility of crack formation is discussed and the methods for increasing ductility and avoiding cracking are given. The influence of solution treatment on the microstructure and mechanical properties are also investigated. It is shown that the stainless steel is mainly composed of austenite phase between which a thin ferrite layer is distributed. The inter-metallic compound AlNi precipitates in the ferrite phase and sigma-phase precipitates at the phase boundaries between the austenite and ferrite. Solution treatment significantly increases the tensile strength and ductility of the stainless steel.

Effect of solution and modification treatments on the crack propagation behaviour of Al-7Si alloy under resonant vibration

In order to investigate the influence of solution treatment and modification treatment on the crack propagation behaviour of A1-7Si alloy under resonant vibration, the unmodified and Sr-modified materials were tested. The experimental results indicate that the resistance to crack propagation is improved after solution treatment for both the unmodified and modified alloys. The improvement of cracking resistance of unmodified alloy is due to the change in the cracking paths from broken-through particles to particle/matrix interfaces. The unmodified alloy possesses better cracking resistance than does the modified alloy after solution treating at 535°C for 2 hours. On the other hand, the modification treatment shows no obvious improvement to cracking resistance. In the modified alloy, the crack paths of the as-cast and solution-treated specimens both preferentially progress toward the interdendritic zones. The as-cast alloy shows this trend more strongly and hence its cracking trajectory is more meandering and branching.

Influence of solution treatment on the microstructure and crystallographic texture of cold rolled and recrystallised low carbon steel

The effects of solution treatment on the texture and microstructure of cold rolled (e = 80 %) and recrystallised (T = 650 °C, salt bath) low carbon steel (mass content of 0.032 % C) were studied using both specimens having a maximum amount of carbon in solution and specimens in the as-hot-rolled state. For the investigations X-ray texture measurements and TEM observations were performed. Deformation was more inhomogeneous in specimens with carbon in solution. In such specimens a strong tendency to the formation of shear bands was observed at plastic strains in excess of 50 %. The specimens with little carbon in solution showed only few shear bands. Increasing contents of carbon in solution led to a degradation of the orientation density of the typical cold rolling texture components. This was attributed to the inhomogeneity of deformation, e.g. the formation of shear bands. The highest tendency to shear band formation was observed in {111} oriented grains. The development of shear bands in the deformation microstructure was interpreted in terms of Taylor theory. The {111} recrystallisation texture of samples with carbon in solution was weaker than in conventionally prepared samples. This observation was explained in terms of random nucleation in the inhomogeneously deformed microstructure and solute drag effects.

18Niマルエージ鋼のマルテンサイト組織におよぼす未再結晶溶体化処理の影響

18Niマルエージ鋼のマルテンサイト組織におよぼす未再結晶溶体化処理の影響

18Niマルエージ鋼の水素脆性におよぼす未再結晶溶体化処理の影響

18Niマルエージ鋼の水素脆性におよぼす未再結晶溶体化処理の影響

18Niマルエージ鋼の強度と靱性におよぼす未再結晶溶体化処理の影響

18Niマルエージ鋼の強度と靱性におよぼす未再結晶溶体化処理の影響