Method for observing metallographic structure of Hastelloy/steel overlaying welding interface

The invention discloses a method for observing a metallographic structure of a Hastelloy/steel overlaying welding interface. The method comprises the following steps of: (1) machining a metallographic observation plane at the C-276 Hastelloy/steel overlaying welding interface, grinding, and rinsing off sand grains; (2) mechanically polishing; (3) taking a stainless steel plate as a cathode, taking a sulfuric acid solution as an electrolytic solution, carrying out electrolysis on the metallographic observation plane, and then, wiping the steel part by using nital; and (4) observing under a microscope. According to the method for observing the metallographic structure of the Hastelloy/steel overlaying welding interface, the sulfuric acid solution is adopted to electrolyze the metallographic observation plane at the C-276 Hastelloy/steel overlaying welding interface, so that the influence of serious etching on steel caused by an etching agent is avoided, and the organization structure of a C-276 Hastelloy overla