Dissimilar steel electron beam welding line ultrasonic testing test block and test method

The invention discloses a dissimilar steel electron beam welding lineing line ultrasonic testing test block and a test method. The test block consists of a parent metal I and a parent metal II, both having a thickness of T; a butt welding lineing line for connecting the parent metal I and the parent metal II is formed between the parent metal I and the parent metal II; the parent metal I and the parent metal II are the same as the to-be-tested dissimilar steel in material and thickness respectively; the welding lineing technology of the butt welding line is consistent with the welding technology of the to-be-tested dissimilar steel; three long cross holes are formed, along the thickness of the test block, on the center line of the butt welding line; the three long cross holes are formed onthe positions, shown in the description, of the test block thickness, sequentially from top to bottom; a notch groove extending along the width direction is formed at the root part, on the center line, of the butt welding li