Straight seam welded pipe surface quenching and tempering heat treatment is usually carried out by induction heating or flame heating. The main technical parameters are surface hardness, local hardness and effective hardened layer depth. Hardness testing can use Vickers hardness tester, Rockwell or surface Rockwell hardness tester can also be used. When the surface heat treatment hardened layer is thick, Rockwell hardness tester can also be used.


 


If the local hardness of parts is required to be high, induction quenching and other methods can be used for local quenching heat treatment. Such a straight seam welded pipe is usually marked with the location of local quenching heat treatment and local hardness value on the drawing. Straight seam welded pipe hardness testing should be carried out in the designated area.


 


The three hardness values of Vickers, Rockwell and Surface Rockwell can be easily converted to each other and converted into standards, drawings or hardness values required by users.