Issues regarding the substitution of materials for flange processing
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I would like to ask whether it is appropriate to use Q235-B instead of grade 20 steel to manufacture flanges?
In most cases, Q235B cannot replace 20-stainless steel flanges; Q235B flanges are generally used only in applications where P≤1.6 MPa. If the conditions for plate-type butt-welded flanges are met, namely a design pressure of ≤1.6 MPa and a design temperature of ≤300°C, then Q235B can be used as a substitute for 20-stainless steel.
If the flange is to meet the specified manufacturing grade, it cannot be replaced.
Replacing good quality items with inferior ones – why bother with substitution? 20# steel rods are readily available after all.
Direct answer: It is inappropriate to use Q235-B to manufacture flanges in place of steel grade 20. ”I agree with the answer from the second floor; under normal circumstances, Q235B cannot be used to replace 20 steel in manufacturing flanges. At low pressure (P≤1.6MPa) ； For plate flat welding flanges at lower temperatures (≤300°C), Q235B can be used as a substitute for 20 steel. Of course, it’s best to follow the design requirements.
“At low pressure (P≤1.6MPa)； For plate flat welding flanges at lower temperatures (≤300°C), Q235B can be used as a substitute for 20 steel. What standard governs this practice?