Unusually rapid closure of stressed fractures, observed in the initial stages of loading and at low temperatures, is examined using models for subcritical crack growth and pressure solution. The model for stress corrosion examines tensile stress concentrations induced at the Hertzian contact of propping fracture asperities, and mediates fracture growth according to a kinetic rate law. Conversel...

Intergranular(IG) fracture due to thermal treatment has been reported in a reactor pressure vessel(RPV) steel of Russian light water last decade. This is attributed grain boundary segregation phosphorus (P) or precipitation carbide, etc.. finding difference microstructure before and after IG cracking; this cannot explain the cause embrittlement. old paradigm follows only correlation. Recently, ...

Normally closed (NC) micro check-valve is used to stop liquid flow when liquid pressure difference across the membrane is lower than the designed cracking pressure. As shown in Figure 2-1, when the applied pressure P is lower than the designed cracking pressure, P c , the NC check-valve is closed, and vice versa. Generally the cracking pressure can be introduced electrically such as electromagn...

The initiating explosive devices are prohibited in rock breaking near the goaf of the highly gassy mine. It is effective and applicable to cracking the hard roof with static cracking agent. By testing the static cracking of cubic limestone (size: 200 × 200 × 200 mm) with true triaxial rock mechanics testing machine under the effect of bidirectional stress and by monitoring the evolution process...

We have previously developed a photosensitive adhesive material that enables microfluidic channel structure formation and subsequent bonding to cover with the aim of simplifying process wafer-scale device fabrication. However, curing required heat treatment at 200 ℃ 180 ℃, respectively, resulting in generation relatively high residual thermal stress. This may lead delamination, warping, crackin...

This paper presents the application of Differential Evolution (DE), an Evolutionary Computation method, for the optimization of Thermal Cracking operation. The objective in this problem is the estimation of optimal flow rates of different feeds to the cracking furnace under the restriction on ethylene and propylene production. Thousands of combinations of feeds are possible. Hence an efficient ...

The microstructure and local mechanical characteristics of thermal spray ferrous coatings have been determined. The emphasis has been on coatings made by the high velocity oxyfuel (HVOF) process, especially the role of Al alloy additives. The oxide phase present in the material and preferred pathways for local cracking and separation have been determined. Thin intersplat oxide layers emerge as ...

In metastable austenitic stainless steels, strain-induced martensitic transformation during plastic deformation enhances work hardening of the material, increasing its strength and in some cases also ductility.1,2) The presence of α’-martensite, however, may increase the susceptibility of these materials to hydrogen embrittlement phenomena, for example delayed cracking.3–6) Delayed cracking can...

Stress corrosion cracking (SCC) of metals is an issue of major concern in engineering since this phenomenon causes many catastrophic failures of structural components in aggressive environments. SCC is even more harmful under cathodic conditions promoting the phenomenon known as hydrogen assisted cracking (HAC), hydrogen assisted fracture (HAF) or hydrogen embrittlement (HE). A common way to as...