Is heat treatment required for the tube sleeves in the main steam pipeline used to install thermocouples after welding is completed?
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This post was last edited by zhaoqingsheng on 2016-6-11 22:38. As the title suggests: For the pipe sleeves used to install thermocouples in power plant main steam pipes, is heat treatment required after welding? (Note: The diameter * wall thickness of the main steam pipe is 325*25; the material used is 12Cr1MoV.) The operating conditions of the main steam pipeline are: pressure of 9.8 MPa ； Temperature: 540°C. The material of the socket used for installing the thermocouple is 304 stainless steel).
Yes, it’s often in these small details that problems arise
540°C – that’s a temperature at which certain effects can be achieved. The tempering temperature for ordinary stainless steel is usually between 300–400°. It’s fine to use it right after welding, but it’s better to wait a few months before using it; tempering is advisable in such cases
Heat treatment is required; when cooled to 300°C, there is no requirement for a specific cooling rate, and natural cooling is sufficient.
The material of the socket used for installing the thermocouple is 304 stainless steel). The material for this pipe socket should be similar to that of the main pipeline