Calculation method for thickness of inner oxide layer of martensitic heat-resistant steel in steam environment

A non-destructive method for enhancing a structural management of a martensitic heat-resistant steel component in a steam environment, wherein the martensitic heat-resistant steel component is 9% Cr martensitic heat-resistant steel component, and the method comprising:

• obtaining operation parameters of the 9% Cr martensitic heat-resistant steel component, wherein the operation parameters comprises a steam temperature T, a steam pressure p, and an operation time t;
• calculating a thickness Y of an inner oxide layer on a wall surface of the 9% Cr martensitic heat-resistant steel component, wherein the thickness Y of the inner oxide layer directly indicates a consumed metal thickness of a component wall, and using a coupled functional model that accounts for a combined influence of the steam temperature and the steam pressure:
• Y=ω*YT+(1−ω)*Yp
• wherein Y is the thickness of the inner oxide layer in the steam environment (μm), YT is a relationship between the steam temperature and the thickness of the inner oxide layer in the steam environment (μm), Yp is a relationship between the steam pressure and the thickness of the inner oxide layer in the steam environment (μm), ω is a weight coefficient representing a relative contribution of the steam temperature and the steam pressure to an inner oxide layer growth, T is the steam temperature (K), p is the steam pressure (MPa), t is time (h);
• and
• determining an effective remaining wall thickness of the 9% Cr martensitic heat-resistant steel component by subtracting the calculated thickness Y from an initial wall thickness, and
• evaluating a risk of pipe failure based on the effective remaining wall thickness, thereby providing an improved basis for preventing pipe burst accidents without requiring destructive physical inspection.