Rare earth high silicon-nickel-chrome alloy cast iron and smelting method thereof

Abstract

The invention relates to a rare earth high silicon-nickel-chrome alloy cast iron, which comprises Fe, Cr, Ni, Mo, Cu, Si, Mn, C, S, P and minor elements such as Nb, V, Zr, N and Re, and is formed by smelting in an electric heater. The alloy cast iron comprises the following alloy components in percentage by weight: 0.50-18.80% of Cr, 0.10-21.50% of Ni, 0.15-3.80% of Mo, 0.20-3.50% of Cu, 2.50-18.50% of Si, 0.60-1.20% of Mn, 0.80-3.20% of C, 0.02-0.15% of S, 0.10-0.20 of P, 0.50-3.20% of Re, a proper amount of Nb, V, Zr and N, and the balance of Fe. The alloy cast iron can be used in a strong corrosive medium under normal operation conditions, and the corrosion resistance of the alloy cast iron can be compared with that of the expensive imported advanced acid-proof stainless steel material. The alloy cast iron can be cast into casting with fine corrosion resistance, and can also be manufactured into various corrosion-resistant devices and fittings by forging, mechanical cutting, welding fabrication and other processes, but has a lower cost, thereby being a cheap and fine new alloy material.

Description

technical field [0001] The invention relates to a rare-earth alloy cast iron manufacturing technology, in particular to a rare-earth high-silicon-nickel-chromium alloy cast iron and a smelting method, belonging to the field of metal smelting. Background technique [0002] Acid corrosion problems will be encountered in metallurgy, chemical industry, chemical fertilizer, petroleum and acid chemical enterprises. Among them, sulfuric acid is the most corrosive liquid medium among the three strong acids, but it is also the most widely applicable strong corrosive liquid medium. my country is the world's largest producer and user of sulfuric acid, and it is also one of the countries most affected by acid corrosion. [0003] At present, the materials of acid pipelines, pumps, valves, acid distributors and other equipment of sulfuric acid production plants in most enterprises in my country are traditionally made of ordinary cast iron, low chromium cast iron or stainless steel with an...

AI Technical Summary

Problems solved by technology

However, ordinary cast iron and low-chromium cast iron have the problems of poor corrosion resistance and small application range due to the congenital deficiency in corrosion resistance of materials.

When the concentration of sulfuric acid is lower than 90% or the acid temperature exceeds 100°C, the corrosion resistance of ordinary cast iron and low-chromium cast iron is significantly reduced

If stainless steel anode protection technology is used, although the service life is longer, in addition to using more expensive stainless steel materials, a set of instruments, meters and power supply equipment such as potentiostats must be configured, which not only increases equipment investment and management costs , and in the specific operation, there are strict process control requirements on the acid temperature and the content of negative ions in the acid, often due to the increase of halogen ions in the medium, or the change of acid temperature and concentration, severe corrosion occurs

If imported high-grade acid-resistant stainless steel materials such as "Sandvik Sx" alloy, "Lewmet55#" alloy and "Hastelloy" alloy with better corrosion resistance are used, although the corrosion resistance is very good, the price will be very expensive