Conveners
M2OrG - Materials III: Processing of Metals and Alloys
- Karl Hartwig (Texas A&M University)
- Dick Reed (Cryogenic Materials, Inc.)
Maraging steels are low carbon, high Ni steels that have an extraordinary combination of high strength, and fracture toughness at room temperature. These steels could be attractive for cryogenic structural fatigue applications with cycle requirements between hundred thousand and a million cycles, however, there is a paucity of cryogenic test data of these steels. Preliminary examinations...
The main aim of this paper is to evaluate the mechanical properties and microstructure of 316LN high-nitrogen austenitic stainless steel after rolling under ambient and cryogenic conditions. Cryorolling was realized after cooling in liquid nitrogen bath at 77 K. During the rolling at ambient temperature (TA) can take place the dynamic recovery of the microstructure. This is strongly retarded...
In response to the ever increasing requirements for all materials that are used in superconducting magnets, this article deals with the possibilities of increasing the mechanical properties of a superalloy used at cryogenic conditions for structural reinforcement or conduit for supercnducting cables.
Typical structural materials for cryogenic temperatures down to 4.2 K are nickel-bearing...
The fatigue life expectations of some contemporary superconducting magnet designs (ITER Central Solenoid and the NHMFL -Series Connected Hybrid) are considerable, with life cycle requirements for the materials in excess of 1 million cycles at the operating stress ranges. Austenitic steels are the material of choice for many cryogenic structural applications and we have generated a moderate...
The microstructure of metals and alloys has a significant impact on material properties.
Therefore a detailed investigation of this characteristic is mandatory for the understanding of the behavior of the material of interest.
Beside of the mechanical behavior the impact of the microstructure on thermal and electrical properties is of importance. At cryogenic temperatures thermal processes...
Temperature dependence on tensile properties in metallic materials is closely related with the crystal structure: bcc materials exhibit strong dependence and then their strength is increased as lowering temperature while the elongation is dramatically decreased: fcc materials are not sensitive on the temperature and show a good ductility even at cryogenic temperature. The binary system of iron...
The effect of mean stress or the stress ratio, R, (ratio of minimum stress to maximum stress) on the high-cycle fatigue properties of Ti-5Al-2.5Sn extra-low interstitial (ELI) forging was investigated at 293 K and 77 K. Fatigue tests were carried out for up to ten million cycles at stress ratios of R=-1, 0.01 and 0.5. It is well known that the static strength of metals increases with a...
Both current and future planned „magnetic fusion reactors" demands very high mechanical properties at cryogenic conditions to ensure superconductivity of magnets and reactor structural integrity at the same time. This paper deals with the possibilities of increasing the mechanical properties of 316LN austenitic stainless steel by means of industrially-feasible thermomechanical processing....
