Method for smelting return scrap of martensitic stainless steel used for impeller

A technology of martensitic stainless steel and return materials, applied in the field of metallurgy, can solve the problems of return materials or waste forgings that cannot be used, and achieve the effects of improving various mechanical performance indicators, reducing defects, and improving performance indicators

Active Publication Date: 2015-03-11
沈阳科金特种材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problems existing in the prior art. After repeated tests and researches, a method for smelting returned martensitic stainless steel for impellers is p

Method used

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  • Method for smelting return scrap of martensitic stainless steel used for impeller
  • Method for smelting return scrap of martensitic stainless steel used for impeller
  • Method for smelting return scrap of martensitic stainless steel used for impeller

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Carry out baking and shot blasting treatment on the return materials and waste forgings produced during the preparation of the impeller, clean the surface of the return materials and waste forgings, and then place them in a vacuum induction furnace at the same time to start vacuuming the vacuum equipment, when the vacuum degree is ≤ 3.2Pa , heat up to 1030°C by power transmission, refining for 15 minutes, and then heat the alloy melt to 1610°C for refining, the refining time is 30 minutes, in which the vacuum degree is controlled to be ≤12.1Pa during the melting process of the alloy melt, and the vacuum degree is ≤3.2 during the refining process Pa; After refining, cool down to the conjunctiva on the surface of the alloy melt. Heat the alloy melt of the conjunctiva to 1550°C and cast it into a primary ingot.

[0025] The chemical composition of the primary ingot was analyzed by weight percentage as Ni 4.18%, Cr 12.85%, Mo 0.61%, Mn 0.87%, Si 0.24%, C 0.039%, and the bal...

Embodiment 2

[0032] Carry out baking and shot blasting treatment on the return materials and waste forgings produced during the preparation of the impeller, clean the surface of the return materials and waste forgings, and then place them in a vacuum induction furnace at the same time to start vacuuming the vacuum equipment, when the vacuum degree is ≤ 3.2Pa At this time, the temperature is raised to 1032°C by power transmission, refining for 16 minutes, and the temperature of the alloy melt is raised to 1620°C for refining. The refining time is 28 minutes. During the melting process of the alloy melt, the vacuum degree is controlled to be ≤12.1Pa, and the vacuum degree is controlled to be ≤3.2 during the refining process. Pa; After refining, cool down to the conjunctiva on the surface of the alloy melt. Heat the alloy melt of the conjunctiva to 1550°C and cast it into a primary ingot.

[0033]The chemical composition of the primary ingot was analyzed by weight percentage as Ni 4.25%, Cr 1...

Embodiment 3

[0040] The production process routes in Examples 1 and 2 are adopted, and the produced impeller forgings are treated in a fixed heat treatment process system, and the obtained mechanical properties are shown in Table 4.

[0041] Table 4 Mechanical properties of impeller products

[0042]

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PUM

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Abstract

The invention relates to a method for smelting return scrap of martensitic stainless steel used for an impeller. The method comprises the following steps that the return scrap and/or waste forged pieces are put into a vacuum induction furnace to be refined, and are cooled and poured to form a primary ingot; after the primary ingot is subjected to chemical component analysis, nickel, manganese, chromium, molybdenum and aluminum intermediate alloys and/or carbon serve as materials for adjustment of elementary components, and the alloy components are adjusted. The primary ingot and nickel, chromium, molybdenum and/or silicon in the materials for adjustment of the elementary components are refined for the second time, heating and pouring are conducted after film forming, alternatively, liquid alloy where a film is formed after secondary refinement is added, the carbon and/or the manganese intermediate alloy are alloyed, and heating and pouring are conducted after film forming, so an electrode cast ingot used for a protective atmosphere electroslag furnace is formed. Electroslag remelting is conducted, and a steel ingot for production of impeller products is prepared. The alloy ingot of the recycle scrap can completely meet the requirement of production of qualified impeller products, the production cost is greatly reduced, requirements of projects are met and economic benefits are created.

Description

technical field [0001] The invention relates to a method for smelting returned materials of stainless steel, in particular to a method for smelting returned materials of martensitic stainless steel for impellers, and belongs to the technical field of metallurgy. Background technique [0002] The martensitic stainless steel (ASTM A-473 S41500) alloy for impeller is a material for nuclear main pump impeller in nuclear power projects. The outstanding features of this alloy are low carbon content and excellent corrosion resistance; high Cr and Ni content; H, Low requirements for harmful gas elements such as O and N. It has a relatively high initial melting temperature, good strength and toughness indicators, and good resistance to cold and heat fatigue. Its composition requirements are shown in Table 1. [0003] Table 1 Chemical composition requirements (wt%). [0004] [0005] Preliminary experiments show that in a fixed heat treatment process (quenching temperature 1052±...

Claims

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Application Information

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IPC IPC(8): C22C33/04C22B9/04C22B9/18
CPCY02P10/25
Inventor 赵忠刚文长春刘莹栾威威萨仁格日乐王春波伦建伟岳景东
Owner 沈阳科金特种材料有限公司
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