N10 material (steel)

Technical Report · Mon Mar 01 04:00:00 EDT 1943

OSTI ID:7306234

Results of some tests are presented, which showed deficiencies in the performance of N10 steel in high-pressure apparatus and gave some suggestions for developing new steels which might have better performance characteristics. It was reported that after only 20,000 hours of operation, withstanding at most 540/sup 0/C in a moderately stressed tube-wall location, some sampled N10 material had shown a strong increase in brittleness and some structural deterioration, as shown by tests for toughness and tensile strength. Toughness and impact resistance seemed to have decreased more strikingly in the test at 20/sup 0/C than in the test at 500/sup 0/C. Extensibility and contractability were significantly reduced. It was suggested that the fact that N10 contained relatively high amounts of both tungsten and vanadium might have had something to do with the difficulties. It was suggested that alloys consisting of chromium and molybdenum and fairly sizable amounts of either tungsten or vanadium but very little of the other might have better characteristics. In this connection it was speculated that high contents of both tungsten and vanadium might have led to a type of super-saturation in the alloy melt, leading to a crystallization which had actually been observed in some samples of the steel which had failed. As an improved steel, it was suggested to develop further the N9 variety of steel in the direction of the earlier N6 variety, except with increased molybdenum and vanadium content, but very little tungsten. The possibility was mentioned of using increased silicon content and possibly titanium as improved binders for the carbon, unless it was decided to hold the carbon content very low. Also it was mentioned that the necessary air-tempering of complete hairpin tubes called for significantly increased chromium content.

• Research Organization: Krupp (Friedr.) G.m.b.H., Essen (Germany, F.R.)
• OSTI ID: 7306234
• Report Number(s): TOM-251-461-462
• Country of Publication: United States
• Language: German

Related Subjects

01 COAL, LIGNITE, AND PEAT
010405 -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
CARBON
CHROMIUM
ELEMENTS
EVALUATION
HEAT TREATMENTS
HIGH PRESSURE
HIGH TEMPERATURE
IRON ALLOYS
IRON BASE ALLOYS
METALS
MOLYBDENUM
NONMETALS
PHYSICAL PROPERTIES
REFRACTORY METALS
SEMIMETALS
SILICON
STEELS
TEMPERING
TITANIUM
TRANSITION ELEMENTS
TUNGSTEN
VANADIUM