| 摘要 |
The invention relates to a component or coupon (26), which component or coupon 5 (26) is used in a thermal machine under extreme thermal and mechanical conditions, whereby said component or coupon (26) is made of an alloy material with a controllable grain size (d), and is in service subjected to an expected temperature and/or stress and/or strain distribution (T(X,Y,Z); a(X,Y,Z); E(X,Y,Z)), which varies with the geometrical coordinates (X,Y,Z) of the component or coupon 10 (26). The component or coupon (26) is improved by having a grain size distribution (d(X,Y,Z)), which depends on said expected temperature and/or stress and/or strain distribution (T(X,Y,Z); o(X,Y,Z); E(X,Y,Z)) such that the lifetime of the 15 component (26) is improved with respect to a similar component with a substantially uniform grain size. (Fig. 4) |
