Phase chemistry and precipitation reactions in maraging steels: Part II. Co-free T-300 steel

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

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Effect of Aging Condition of Tensile Properties of Iron-Nickel-Titanium Maraging Steels

Transactions of the Iron and Steel Institute of Japan ◽

10.2355/isijinternational1966.22.848 ◽

1982 ◽

Vol 22 (11) ◽

pp. 848-854 ◽

Cited By ~ 2

Author(s):

Ko SOENO ◽

Masatoshi TSUCHIYA

Keyword(s):

Tensile Properties ◽

Nickel Titanium ◽

Aging Condition ◽

Maraging Steels ◽

Iron Nickel

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BETHLEHEM LUKENS PLATE SPARTAN

Alloy Digest ◽

10.31399/asm.ad.sa0518 ◽

2003 ◽

Vol 52 (8) ◽

Keyword(s):

Fracture Toughness ◽

Yield Strength ◽

Tensile Properties ◽

High Strength Steels ◽

High Strength ◽

Tensile Yield Strength ◽

Precipitation Reactions

Abstract Bethlehem Lukens Plate (BLP) offers five grades of Spartan high-strength steels with tensile yield strength over 690 MPa (100 ksi). These alloys contain copper for precipitation reactions. They also have improved weldability and toughness compared to ASTM A 514 and A 543 grades. This datasheet provides information on composition, microstructure, hardness, and tensile properties as well as fracture toughness. It also includes information on forming and joining. Filing Code: SA-518. Producer or source: Bethlehem Lukens Plate.

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Thermal Decomposition of Li(NTO)·2H2O and Na(NTO)·H2O (NTO = Anion of 3-Nitro-1,2,4-triazol-5-one): Kinetics Derived from T-jump/FTIR Spectroscopy

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20060129 ◽

2006 ◽

Vol 71 (1) ◽

pp. 129-137 ◽

Cited By ~ 1

Author(s):

Yuanhua Sun ◽

Tonglai Zhang ◽

Jianguo Zhang ◽

Xiaojing Qiao ◽

Li Yang ◽

...

Keyword(s):

Ftir Spectroscopy ◽

Energetic Material ◽

Burning Surface ◽

High Sensitivity ◽

Control Voltage ◽

Differential Scanning Colorimetry ◽

Voltage Trace ◽

Dsc Method ◽

Phase Chemistry ◽

Kinetics Of

A "snapshot" simulation of the surface reaction zone is captured by a thin film of material heated rapidly to temperatures characteristic of the burning surface by using the T-jump/FTIR spectroscopy. The time-to-exotherm (tx) kinetics method derived from the control voltage trace of the Pt filament can be introduced to resolve the kinetics of an energetic material owing to its high sensitivity to the thermochemical reactions. The kinetic parameters of the two title compounds are determined under different pressures. The results show that Li(NTO)·2H2O and Na(NTO)·H2O (NTO = anion of 3-nitro-1,2,4-triazol-5-one) exhibit weak pressure dependence, their decomposition is dominated by the condensed phase chemistry irrespective of the pressure in the 0.1-1.1 MPa range. The values of Ea determined here are smaller than those given by a traditional non-isothermal differential scanning colorimetry (DSC) method, which might be resembled as the surface of explosion more closely and enabled the pyrolysis surface to be incorporated into models of steady and possibly unsteady combustion. The kinetics can also be successfully used to understand the behavior of the energetic material in practical combustion problems.

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