Step cooling Test of LAS materials (2 1/4 Cr - 1Mo and 3 Cr-1Mo)

[khati]

Hiee,

1. Why do we specify step cooling test for Gr.22 materials ?
2. What is the advantages of step cooling test?
3. Is it necessary to give setp cooling test for Gr.22 materials?


Regards.

 

[stanweld]

The step cooling tests were developed to provide information as to the potential for temper embrittlement of the alloys. They were originally developed and employed for heavy wall hydrocracker reactor vessels.

 

[Guest102023]

The problem of temper embrittlement in these steels arises after long exposure at high temperatures, as would be experienced by reactor vessels. The primary factor is tramp elements, and the best way to combat it is controlling these to low levels. The J-factor applies to base metal and the Bruscato X-factor to weld metal. Avoidance of TE also depends on correct heat treatment.

The step cooling test is a greatly accelerated way to simulate embrittlement conditions. I have posted a couple of papers that describe it.

 

[Guest102023]

The second -