Urgent! Urgent! Urgent! Allowable stress for materials
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May I ask what the allowable stress is for 304 material at room temperature?:)
ASME allowable stresses are determined according to the following rules: When the operating temperature is below the temperature at which creep and fatigue strength govern the allowable stress, the allowable stress for the material is the lowest of the following values: (1) the minimum tensile strength specified at room temperature divided by 3.5, i.e., σb / 3.5; (2) the tensile strength at the operating temperature multiplied by 1.1/3.5, i.e., σb / 3.18; (3) the minimum yield strength specified at room temperature multiplied by 2/3, i.e., σs / 1.5; (4) the yield strength at the operating temperature multiplied by 2/3, or 0.9 times the yield strength at that temperature – the latter option being applicable only to austenitic stainless steels for which slight deformation is not harmful. That is, σts / 1.5, provided that this value is less than σts / 1.1. The denominator values in the above items are respectively the safety factors under those specified conditions. Under normal circumstances, the allowable stress can be selected as σs/1.5.
304 is equivalent to 0Cr18Ni9, and its allowable stress at room temperature is 122 MPa.
Please refer to Table 4-3 of GB150, with the temperature set at 20°C.