Low-temperature mechanical properties of Fe–0.06C–18Cr–10Ni–0.4Ti austenitic steel determined using ring-pull tensile tests and microhardness measurements

AbstractThe effect of austempering parameters on the microstructure and mechanical properties of 27MnCrB5-2 steel has been investigated by means of: dilatometric, microstructural and fractographic analyses; tensile and Charpy V-notch (CVN) impact tests at room temperature and a low temperature.Microstructural analyses showed that upper bainite developed at a higher austempering temperature, while a mixed bainitic-martensitic microstructure formed at lower temperatures, with a different amount of bainite and martensite and a different size of bainite sheaf depending on the temperature. Tensile tests highlighted superior yield and tensile strengths (≈30%) for the mixed microstructure, with respect to both fully bainitic and Q&T microstructures, with only a low reduction in elongation to failure (≈10%). Impact tests confirmed that mixed microstructures have higher impact properties, at both room temperature and a low temperature.

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Experimental Study on Low Temperature Mechanical Properties of HTPB Propellant

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.310.124 ◽

2013 ◽

Vol 310 ◽

pp. 124-128 ◽

Cited By ~ 2

Author(s):

Xiao Jun Zhang ◽

Xin Long Chang ◽

Shi Ying Zhang ◽

Jie Tang Zhu

Keyword(s):

Mechanical Properties ◽

Low Temperature ◽

Tensile Test ◽

Room Temperature ◽

Maximum Stress ◽

Tensile Tests ◽

Maximum Tensile Stress ◽

Uniaxial Tensile ◽

Stress Strain ◽

Htpb Propellant

In order to investigate low temperature mechanical characteristics of HTPB (hydroxy-terminated polybutadiene binder) propellant, uniaxial tensile tests at both the low temperature and room temperature after short storage at low temperature were conducted and SEM (scanning electron microscopy) was used to observe fracture surfaces. The mechanical properties and stress-strain curves were obtained. The experimental results show that matrix tearing and particle brittle fracture occur in low temperature tensile test, but only particle/matrix interface de-wetting in room temperature tensile test. Low temperature stress-strain curves of propellant appear obviously yield region, and the yield degree is involved to the low temperature value. The low temperature mechanical properties such as maximum tensile stress, elastic modulus and strain at maximum stress against temperature are different from room temperature mechanical properties.

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Acceleration of Bainitic Transformation in Nanostructured, Low Temperature Bainitic Steels by Using of Thermodynamic Model

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.172-174.214 ◽

2011 ◽

Vol 172-174 ◽

pp. 214-220 ◽

Cited By ~ 2

Author(s):

Mir Nariman Yoozbashi ◽

Sasan Yazdania

Keyword(s):

Mechanical Properties ◽

Low Temperature ◽

Thermodynamic Model ◽

Uniform Elongation ◽

Recent Decade ◽

Tensile Tests ◽

Bainitic Transformation ◽

Cambridge University ◽

Bainitic Steels ◽

Hot Rolled

Nanostructured, low temperature bainitic steels with remarkable combination of ultimate tensile strength of about 2.5 GPa and high uniform elongation have been developed in the recent decade. To accelerate the bainitic transformation in theses steels, new chemical composition was designed by MUCG83 thermodynamic model which was developed in Cambridge University by Bhadeshia. The samples, prepared from the hot rolled ingots, were transformed isothermally at the temperature range of 200 to 300°C for different times. The microstructure and mechanical properties of the samples were evaluated by XRD, SEM, hardness and tensile tests. The results showed a unique microstructure and good mechanical properties like other bainitic steels, while the needed time for the completion of transformation is shorter compared to that of others.

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