Effect of Lowering Si on the Properties of 1Cr-1Mo-V Casting
1984 Volume 70 Issue 2 Pages 254-261
Details
1984 Volume 70 Issue 2 Pages 254-261
Effect of lowering Si content on the porosity frequency, rupture strength and weldability of Cr-Mo-V large castings for turbine casing and valve was investigated, using large test specimens taken from valve castings having low and high Si content. The results are summarized as follows.
(1) Deoxidation of low Si cast steel is achieved completely by 0.1% Fe-Ti addition.
(2) Low Si casting has no inverse V segregation and small amounts of porosity as the results of fine dendrite structure.
(3) There is no difference, between low Si and conventional Si castings, in hardenability and strength at ambient temperature to 566°C.
(4) Creep rupture strength is improved by lowering Si content.
(5) Low Si casting possesses better weldability concerning cold cracking and reheat cracking than conventional Si casting.
