Correlation of Yield Strength and Tensile Strength with Hardness for Steels
03 Apr 2008-Journal of Materials Engineering and Performance (Springer US)-Vol. 17, Iss: 6, pp 888-893
TL;DR: In this paper, the authors used regression analysis to determine the correlation of the yield strength and the tensile strength to the diamond pyramid hardness values for over 150 nonaustenitic, hypoeutectoid steels.
Abstract: Hardness values as well as yield and tensile strength values were compiled for over 150 nonaustenitic, hypoeutectoid steels having a wide range of compositions and a variety of microstructures. The microstructures include ferrite, pearlite, martensite, bainite, and complex multiphase structures. The yield strength of the steels ranged from approximately 300 MPa to over 1700 MPa. Tensile strength varied over the range of 450-2350 MPa. Regression analysis was used to determine the correlation of the yield strength and the tensile strength to the diamond pyramid hardness values for these steels. Both the yield strength and tensile strength of the steels exhibited a linear correlation with the hardness over the entire range of strength values. Empirical relationships are provided that enable the estimation of strength from a bulk hardness measurement. A weak effect of strain-hardening potential on the hardness-yield strength relationship was also observed.
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24 Oct 2018-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, a systematic investigation was conducted on the microstructure and mechanical properties of the produced struts, which possessed hierarchical microstructures consisting of cellular sub-grain structures inside columnar grains.
Abstract: Stainless steel 316L (SS316L) vertical struts with various diameters ranging from 0.25 mm to 5 mm were manufactured by laser powder bed fusion (LPBF) process. A systematic investigation was conducted on the microstructure and mechanical properties of the produced struts. The struts possessed hierarchical microstructures consisting of cellular sub-grain structures inside columnar grains. The primary dendrite arm spacing (PDAS) of the cellular sub-grains decreased monotonically with increasing strut diameter until reaching a plateau after 1 mm. In contrast, the columnar grain width did not show a clear relationship with respect to the variation in the strut diameter. A to texture transition along the building direction (BD) of the struts was observed as the strut diameter decreased from 5 mm to 0.25 mm, which was attributed to the change of the heat extraction direction. Microstructure-property relations were established via Hall-Petch type correlations between the PDAS and the microhardness as well as the PDAS and the strengths of the struts, suggesting the importance of the role played by the cellular sub-grain structures in the strengthening of LPBF manufactured SS316L. Electron backscatter diffraction (EBSD) analysis confirmed that the strong texture within the thicker struts promoted the twinning-induced plasticity, and thus resulted in a better strength-ductility combination compared with that of the thinner struts with texture or weak texture.
112 citations
17 Apr 2015-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the relationship between Vickers hardness, yield stress and tensile strength was analyzed by combining data from two independent studies involving 7010 alloy plate and a rectilinear forging.
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104 citations
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96 citations
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DOI•
01 Jul 1971TL;DR: In this paper, it was shown that the 0.2 pct offset yield strength of a material can be obtained from simple hardness measurements using the expression σ y = (H/3)(0.1) m-2cffff, where H is the Diamond pyramid hardness and m is Meyer's hardness coefficient.
Abstract: It is shown that the 0.2 pct offset yield strength of a material (in kg per sq mm) can be obtained from simple hardness measurements using the expression σ
y
= (H/3)(0.1)
m-2
, whereH is the Diamond pyramid hardness andm is Meyer’s hardness coefficient. This expression holds for brass, steel in either the cold rolled or tempered condition, and aluminum alloys in either the cold rolled or aged condition. It is also shown that the above expression can be derived from a simple model assuming σ = K∈
n
as the stress strain relationship.
442 citations
15 Aug 2005-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, microhardness maps of cross-sections of high pressure diecast test bars of AZ91 have been determined, and the mean hardness obtained by integrating the micro hardness maps over the entire cross-section increased with decreasing thickness of the bars, and was found to be in good correlation with each bar's yield strength.
Abstract: Microhardness maps of cross-sections of high-pressure diecast test bars of AZ91 have been determined. Specimens with rectangular cross-sections, 1, 2 and 3 mm thick, or with a circular cross-section 6.4 mm in diameter, have been studied. The hardness is generally higher near the edges in all specimens, and more so near the corners of the rectangular specimens. The hardness at the center of the castings is generally lower, due to a coarser solidification microstructure and the concentration of porosity. The evidence confirms that the surface of the castings is harder than the core, but it does not support the concept of a skin with a sharp and definable boundary. This harder layer is irregular in hardness and depth and is not equally hard on opposite sides of the casting. The mean hardness obtained by integrating the microhardness maps over the entire cross-section increased with decreasing thickness of the bars, and was found to be in good correlation with each bar's yield strength.
81 citations
TL;DR: In this paper, the influence of varying the thermal processing parameters on the physical and mechanical properties of 7075 T6 aluminum alloy was studied and an excellent correlation was found between the tensile strength and hardness.
80 citations