| 摘要 |
In an internal combustion engine, a cylinder member, such as a valve, a seat portion, a piston or a cylinder liner, is provided with a welded high-temperature corrosion-resistant facing alloy. The hardness of the welded alloy has been increased by means of a precipitation hardening mechanism based on a solid-state phase transformation, where the temperature for activation of the precipitation hardening mechanism is above the operating temperature of the alloy. The precipiation hardening mechanism acts so slowly that the alloy substantially does not harden at the welding on to the cylinder member, but only hardens during a subsequent heat treatment at a temperature higher than the activation temperature for the precipitation hardening mechanism. Expressed in percentage by weight and apart from commonly occurring impurities, the nickel-based facing alloy comprises from 40 to 51 % Cr, from 0 to 0.1 % C, less than 1.0 % Si, from 0 to 5.0 % Mn, less than 1.0 % Mo, from 0.05 to less than 0.5 % B, from 0 to 1.0 % Al, from 0 to 1.5 % Ti, from 0 to 0.2 % Zr, from 0.5 to 3.0 % Nb, an aggregate content of Co and Fe of maximum 5.0 %, maximum 0.2 % O, maximum 0.3 % N and the balance Ni.
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