Back to results
US 2003/0188808 A1Published application
Thermal fatigeue resistant cast steel
AssigneeDaido Steel Co., Ltd.
InventorsShigeki Ueta, Shuji Hamano, Toshiharu Noda
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeDaido Steel Co., Ltd.
InventorsShigeki Ueta, Shuji Hamano, Toshiharu Noda
Estimating the term…
ABSTRACT OF DISCLOSURE Disclosed is a heat resistant cast steel having not only good heat resistance but also good thermal fatigue resistance, which is suitable as the material for engine parts, particularly, such as exhaust gas manifold and turbo-housing, which are repeatedly exposed to such a high temperature as 900° C. or higher. The heat resistant cast steel comprises, by weight percent, C: 0.2-1.0%, Ni: 8.0-45.0%, Cr: 15.0-30.0%, W: up to 10% and Nb: 0.5-3.0%, provided that [%C]-0.13[%Nb]: 0.05-0.95%, the balance being Fe and inevitable impurities, and the cast structure contains dispersed therein, by atomic percent, MC-type carbides: 0.5-3.0% and M23C6-type carbides: 0.5-10.0%. The matrix of the steel is an austenitic phase mainly composed of Fe—Ni—Cr and the steel has the mean coefficient of thermal expansion in the range from room temperature to 1050° C. up to 20.0×10−4 and a tensile strength in the temperature range up to 1050° C. 50 MPa or higher.
A heat resistant cast steel having good thermal fatigue resistance, characterized in that the steel structure contains in the form of dispersion therein, in atomic percent, MC-type carbides 0.5-3.0% and M23C6-type carbides 5-10%, that the matrix consists essentially of an austenitic phase mainly composed of Fe—Ni—Cr, and a mean coefficient of thermal expansion in the range from room temperature to 1050° C. up to 20.0×10−4 and a tensile strength in the temperature range up to 1050° C. 50 MPa or higher.
Dependencies are inferred from the claim text.