Double-disk flange and through-wall flange spheroidal graphite cast iron straight pipe integral casting technology

Abstract

The invention discloses a double-disk flange and through-wall flange spheroidal graphite cast iron straight pipe integral casting technology. A lower section flange outer die, a through-wall flange section outer die, a transitional section outer die, an upper section flange outer die, a steel pipe framework, a transitional section core, a parting surface locating table, a through-wall flange, a screw rod and the like are involved; the screw rod is arranged on a lower pressing plate and fixed at the lower part of the lower pressing plate through a nut; a lower section core, a core connection sleeve and the through-wall flange are arranged on the lower pressing plate; the through-wall flange section outer die is arranged on the lower section flange outer die; the transitional section outer die and the upper section flange outer die are arranged on the through-wall flange section outer die; an ingate is arranged at the right middle part of the lower section core; the transitional section core and the parting surface locating table are arranged at the right part of the lower section core. According to the double-disk flange and through-wall flange spheroidal graphite cast iron straight pipe integral casting technology, by horizontal parting and vertical stepped negative pressure pouring, the molding qualification rate is increased, and the quality is more reliable; pressure casting enables an alloy structure to be more compact, so that the environmental protection is facilitated, dust can be all recycled, and environmental-friendly casting is really realized; the technology is applied to the technical field of integral casting of metals.

Description

technical field [0001] The present invention relates to a double-disc flange and through-wall flange nodular cast iron straight pipe integral casting technology in the technical field of metal integral casting technology, in particular to a ductile iron double-disk through-wall flange straight pipe with DN100-DN200×3 meters or more Integral casting. Background technique [0002] At present, most of the ductile iron double-flange straight pipes and wall-penetrating double-coil pipes used for pressure bearing are manufactured by welding. Due to the limitation of cast iron welding materials, the welding parts are all "heterogeneous" welds. Due to the different materials of the weld and the substrate, and the interference of the heat-affected zone of the weld, it is difficult for the mechanical properties of the welded flange to meet the standard requirements. According to ISO2531; 2009 international standard and GB / T13295-2013 national standard, the minimum tensile strength of...

AI Technical Summary

Problems solved by technology

Among them, the main problems of ordinary sand casting are uneven wall thickness and bending deformation; the main problems of lost foam casting are slag inclusion, many pores, and high water leakage rate in hydraulic test.

In particular, it should be pointed out that the smaller the pipe diameter and the longer the length, the greater the probability of the above-mentioned defects. It is difficult to form a flange pipe with a length of less than DN200 and a length of more than 2 meters. Even if it is formed, the pass rate is very low. , unable to meet market demand

Images