PREVENTION OF CRACK IN BUILD UP WELD ZONE

摘要

PURPOSE:To prevent a high-temp. crack and embrittlement crack as well as peeling crack arising from the hydrogen embrittlement by controlling the Cr equiv. and Ni equiv. of a build-up metal within a specific range. CONSTITUTION:The Cr equiv. is controlled to 18.0-21.8 and the Ni equiv. to 10.2-12.8 and the chemical compsn. contg. the Cr equiv. and Ni equiv. within the 4 point range specified as follows is used in the stage of build-up welding of an austenitic stainless steel to an alloy steel for structural purpose with large heat input: The chemical compsn. is formed of the 4 points; the 1st point is 18.0 Cr equiv. and 11.0 Ni equiv., the 2nd point is 19.8 Cr equiv. and 12.8 Ni equiv., the 3rd point is 21.8 Cr equiv. and 12.8 Ni equiv. and 4th point is 19.0 Cr equiv. and 10.2 Ni equiv. The ferrite is precipitated by the above- mentioned method, by which the high-temp. crack and embrittlement crack as well and peeling crack arising from the hydrogen embrittlement are prevented.