A test plan for sustained load fracture control verification

An example test plan for sustained load fracture control verification is presented. Two sustained load fracture problems have been chosen: stress corrosion cracking of titanium alloy Ti-6Al-4V, and gaseous hydrogen embrittlement of the nickel-base superalloy Inconel 718. The plan is worked out in detail, including materials and heat treatments,...

Spacecraft sustained load fracture control

The opportunities for sustained load fracture control in spacecraft are indicated. Emphasis is given to verification by small-scale laboratory testing.

Corrosion fatigue crack arrest in aluminium alloys

The economic life of airframes is largely determined by widespread initiation and growth of fatigue cracks at low stress intensities. Any factor reducing the low stress intensity fatigue damage rate could, if controllable, increase the structural durability. One such factor is corrosion fatigue crack arrest. Corrosion product build-up within a...

Compressibility and fugacity of gaseous hydrogen

The concept of fugacity is explained. Application of compressibility and fugacity data in hydrogen embrittlement calculations is discussed. Equations of state are reviewed. Compressibility factors and fugacity coefficients are calculated. A best estimate is proposed.

Breukvlakonderzoek

In this report an attempt is made to give an overview of the various aspects involved in a fracture surface investigation, stating with a definition of fractography and why it is done. Then the equipment needed is discussed, including stereo-microscopes, optical microscopes, transmission and scanning electron microscopes, and micro-analysis...

Study of the growth of stress corrosion cracks in the aluminum alloy 7075. Part III: Continuation of the investigation on the influence and the role of the corrosion potential and the halide anion

SEN specimens of 70T5 alloy loaded in bending have been used to determine time to failure and the crack propagation rate as a function of K, the stress intensity factor, and of the electrical potential in 3 wt % aqueous solutions of NaCl, NaBr and Nal with p values of 3 and 7. The SC tests were supplemented by potentio-kinetic polarization tests...

Hydrogen embrittlement 0f 4340 steel by cadmium electroplating; interim report no. 1.

Hydrogen embrittlement of the circumferentially notched round specimen

Delayed failure test results for hydrogenated and cadmium plated specimens, tested by Johnson, Korlet and Troiano, have been analyzed on the basis of equations developed by the author. It is found that in a non-homogeneous stress field the hydrogen diffuses to and accumulates at the elastic-plastic interface. The local hydrogen concentration...