CN101560633A

CN101560633A - Technical method for producing heat-resisting alloy steel casting below 1000 DEG C

Info

Publication number: CN101560633A
Application number: CNA2009101434384A
Authority: CN
Inventors: 罗琪; 朱瑞卿; 张良楠
Original assignee: YELONG PRECISION MACHINERY CO Ltd
Current assignee: YELONG PRECISION MACHINERY CO Ltd
Priority date: 2009-05-26
Filing date: 2009-05-26
Publication date: 2009-10-21

Abstract

The invention discloses a technical method for producing a heat-resisting alloy steel casting below 1000 DEG C. The chemical components of the materials of the alloy steel casting are as follows: not less than 0.20 percent and not more than 0.48 percent of C, not less than 19 percent and not more than 22 percent of Cr, not less than 10 percent and not more than 13.5 percent of Ni, 1.2 percent of Si, not less than 0.7 percent and not more than 1.5 percent of Mn, 0.045 percent of P, not less than 0.03 percent and not more than 0.14 percent of S, and not less than 1.2 percent and not more than 1.8 percent of Nb; the microstructure of the adopted materials comprises austenitic and interdendritic chromium carbide. The invention has the advantages of good casting performance and machining performance, significant reduction of production cost and being widely applied to the production of vehicle turbine shells.

Description

A kind of processing method that is used for the refractory alloy steel casting below 1000 ℃

Technical field

The present invention relates to the heat-resistant casting steel preparing technical field, relate in particular to a kind of processing method that is used for the refractory alloy steel casting below 1000 ℃.

Background technology

Face the enforcement of automobile industry Europe five emission standards, the efficient of motor car engine will promote significantly, and the exhaust temperature of engine emission can reach 900 ℃-1150 ℃; There are deficiencies such as castability is poor, processing cutting ability difference in the refractory alloy stainless material of European standard, ASTM standard and iso standard defined at present, and for example the automobile engine exhaust system parts are applicable to the heat-resistant casting steel under the specified temp.Existing ferritic stainless steel is meant that chromium content at 11%-30%, has body-centered cubic crystal structure, in the use based on the stainless steel of ferritic structure; Ferrite stainless steel can be used on to be decorated and the auto exhaust field, the ferrite stainless steel that traditional continuous casting-rolling-annealing process is produced is in the process of fabricated product, surface quality is poor, deep drawability is poor, often the deviation owing to chemical ingredients causes the inhomogeneous and anisotropic of material deformation and performance thereof, thereby makes forming property very poor.

Summary of the invention

At above defective, the purpose of this invention is to provide a kind of have advantages of good casting and machining property, the processing method that is used for the refractory alloy steel casting below 1000 ℃ that production cost is lower, to solve the deficiency of existing processing method.

For achieving the above object, the present invention is achieved through the following technical solutions:

A kind of processing method that is used for the refractory alloy steel casting below 1000 ℃, the chemical ingredients of its Alloy Cast Steel spare raw material is: 0.20%≤C≤0.48%, 19%≤Cr≤22%, 10%≤Ni≤13.5%, Si=1.2%, 0.7%≤Mn≤1.5%, P=0.045%, 0.03%≤S≤0.14%, 1.2%≤Nb≤1.8%; The material microstructure that adopts is made up of the carbide of austenite and interdendritic chromium, the processing method that is adopted comprises: casting mold is incubated 1-1.5 hour in 900 ℃-950 ℃ moderate oven, put into induction furnace with behind the stainless steel raw material preheating to 200 ℃-300 ℃, when reaching 900 ℃-1200 ℃, temperature in induction furnace, feeds rare gas element by air feeder, then molten steel is poured into rapidly to guarantee carrying out casting then at 800 ℃ of left and right sides temperature lower mold casting; It is to be incubated at least 2.5 hours under 800 ℃ of-900 ℃ of temperature that product after the casting-up is put into the High Temperature Furnaces Heating Apparatus temperature environment, cools to room temperature then with the furnace, and the product after the annealing is roughly ground processing.

The beneficial effect that is used for the processing method of the refractory alloy steel casting below 1000 ℃ of the present invention is: have advantages of good casting and machining property, can significantly reduce production costs, can be widely used in the production of automobile turbine case.

Embodiment

Embodiment 1

The described processing method that is used for the refractory alloy steel casting below 1000 ℃ of the embodiment of the invention, the chemical ingredients of its Alloy Cast Steel spare raw material is: C=0.20%, Cr=19%, Ni=10%, Si=1.2%, Mn=0.7%, P=0.045%, S=0.03%, Nb=1.2%; The material microstructure that adopts is made up of the carbide of austenite and interdendritic chromium, and the processing method that is adopted may further comprise the steps:

(1) above raw material is packed in order vacuum oven burner hearth bottom places Riving Box stand-by other element material, casting mold is placed in 900 ℃-950 ℃ the moderate oven insulation 1-1.5 hour, takes out rapidly to be placed on the iron plate of vacuum melting furnace;

(2) put into induction furnace with behind the stainless steel raw material preheating to 200 ℃-300 ℃, furnace charge all melts the back suitable interpolation element of adding and carries out refining, when temperature reaches 900 ℃-1200 ℃, in induction furnace, feed rare gas element, thereby carry out melting completely by air feeder;

(3) when temperature reaches 1600 ℃, pour argon gas, the vacuum chamber internal gas pressure is reached-0.05Pa, then molten steel is poured into rapidly to guarantee carrying out casting then at 800 ℃ of left and right sides temperature lower mold casting;

(4) product after the casting-up being put into the High Temperature Furnaces Heating Apparatus temperature environment is to be incubated at least 2.5 hours under 800 ℃ of-900 ℃ of temperature, cools to room temperature then with the furnace, and the product after the annealing is roughly ground processing.

Embodiment 2

The described processing method that is used for the refractory alloy steel casting below 1000 ℃ of the embodiment of the invention, the chemical ingredients of its Alloy Cast Steel spare raw material is: C=0.48%, Cr=22%, Ni=13.5%, Si=1.2%, Mn=1.5%, P=0.045%, S=0.14%, Nb=1.8%; The material microstructure that adopts is made up of the carbide of austenite and interdendritic chromium, and the processing method that is adopted may further comprise the steps:

(1) above raw material is packed in order vacuum oven burner hearth bottom places Riving Box stand-by other element material, casting mold is placed in 850 ℃-950 ℃ the moderate oven insulation 1-1.5 hour, takes out rapidly to be placed on the iron plate of vacuum melting furnace;

(2) put into induction furnace with behind the stainless steel raw material preheating to 100 ℃-300 ℃, furnace charge all melts the back and adds suitable interpolation element and carry out refining, feeds rare gas element by air feeder in induction furnace when temperature reaches 1100 ℃, thereby carries out melting completely;

Claims

1, a kind of processing method that is used for the refractory alloy steel casting below 1000 ℃, it is characterized in that: the chemical ingredients of its Alloy Cast Steel spare raw material is: 0.20%≤C≤0.48%, 19%≤Cr≤22%, 10%≤Ni≤13.5%, Si=1.2%, 0.7%≤Mn≤1.5%, P=0.045%, 0.03%≤S≤0.14%, 1.2%≤Nb≤1.8%; The material microstructure that adopts is made up of the carbide of austenite and interdendritic chromium.

2, the processing method that is used for the refractory alloy steel casting below 1000 ℃ according to claim 1, it is characterized in that: it is to be incubated at least 2.5 hours under 800 ℃ of-900 ℃ of temperature that the product after the casting-up is put into the High Temperature Furnaces Heating Apparatus temperature environment, cool to room temperature then with the furnace, the product after the annealing is roughly ground processing.