This International Standard specifies: a) the determination of mass gain; b) the surface inspection of products of zirconium and its alloys when corrosion tested in water at 360 °C or in steam at or above 400 °C; c) that the tests in steam shall be performed at 10.3 MPa (1 500 psi); This International Standard is applicable to wrought products, castings, powder metallurgy products and weld metals. This method has been widely used in the development of new alloys, heat treating practices and for the evaluation of welding techniques, and should be utilized in its entirety to the extent specified for a product acceptance test, rather than merely a means of assessing performance in service.