Ultimate Strength (Su) Calculator
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Brinell Hardness (HB) Calculator
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Hardness and Ultimate Strength
Hardness and ultimate tensile strength (SuS_u) are both indicators of a material’s resistance to deformation, but they measure different aspects:
- Hardness refers to a material’s resistance to indentation or scratching. It’s commonly measured using tests like the Brinell, Rockwell, or Vickers hardness tests, where a hard indenter is pressed into the material’s surface.
- Ultimate Tensile Strength (SuS_u) is the maximum stress a material can withstand while being stretched or pulled before it breaks. It’s a measure of a material’s overall strength in tension.
The two properties are related because materials with higher hardness values generally have higher ultimate strengths. Empirical relationships, like those shown in the formulas you provided, allow engineers to estimate SuS_u from hardness values, especially when direct tensile testing isn’t feasible. However, these are approximations, as the relationship between hardness and SuS_u can vary with material type and composition.
The equations given relate Brinell hardness (HB) to the ultimate tensile strength (Su) for different materials:
For Steel:
Su=0.5×HB (in ksi)
Su=3.4×HB (in MPa)
These equations provide a rough estimate of Su based on hardness for steels, where the tensile strength increases proportionally with hardness.
For Cast Iron:
Su=0.23×HB−12.5 (in ksi)
Su=1.58×HB−86(in MPa)
These equations account for cast iron’s different material properties, where hardness increases do not correspond to tensile strength as directly as in steel.
These formulas are useful approximations for predicting strength based on hardness tests, especially when direct tensile testing isn’t practical.
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TensorConnect project 2024 by pttensor.com Author: Caesar Wiratama