Abstract
Phase dependence of tensile strength of stainless steel samples during and after solidification has been investigated by a high temperature tensile test. The experimental technique enables the sample to melt and solidify without a crucible, and to measure a minute load in a solidification temperature range. The tensile strength of samples is depended on phase but not content of chromium and nickel.
Empirical equations of the tensile strength of δ phase and γ phase are established from experimental results.
σδ=0.013(Ts-T)+1.7, MPa
σγ=0.061(Ts-T)+8.0, MPa where Ts is solidus temperature and T is temperature.
The tensile strength of δ phase sample is smaller than that of γ phase, and temperature dependence of tensile strength of δ phase is smaller than that of γ phase. The tensile strength of two phase (δ+γ) is estimated from next equation.
σ(δ+γ)=σδ·fδ+σγ·fγ, MPa where, fδ and fγ are the fractions of δ phase and γ phase, respectively.
18mass%≤Cr≤25mass%, 4mass%≤Ni≤25mass%, 1473K≤T≤1850K
This estimated value is in good agreement with measured value.
