The optimum welding conditions for overlay welding of 30Cr-2Mo clad steel with 19Cr-2Mo-0.25Zr steel filler metal for the first layer and 30Cr-2Mo steel filler metal for the upper layers have been investigated.
Mechanical properties of the overlay welds of 30Cr-2Mo clad steel with these filler metals have also been examined.
Experimental results have shown that an automatic TIG welding, which can provide a constant penetration ratio on overlay welding, was a suitable method for the fabrication of a device in the chemical plant made of 30Cr-2Mo clad steel.
Mechanical properties like as tensile stress, elongation and bend ductility of the overlay welds fabricated with 19Cr-2Mo-0.25Zr steel filler metal for the first layer and 30Cr-2Mo steel filler metal for the upper layers on a low alloy steel, respectively, were satisfied with ones specified in the JIS standard.
The notch toughness of the overlay welds was almost same as one of 30Cr-2Mo steel base metal and the cladding metal of 30Cr-2Mo clad steel.
In addition, the test results of cold-working and hot-working, which was indispensable to the fabrication of a device in the chemical plant, have indicated that 30Cr-2Mo clad steel had an excellent formability.
