CN110648421B - Method for calculating thickness of decarburized layer on surface of decarburized spring steel - Google Patents

Method for calculating thickness of decarburized layer on surface of decarburized spring steel Download PDF

Info

Publication number
CN110648421B
CN110648421B CN201910865995.0A CN201910865995A CN110648421B CN 110648421 B CN110648421 B CN 110648421B CN 201910865995 A CN201910865995 A CN 201910865995A CN 110648421 B CN110648421 B CN 110648421B
Authority
CN
China
Prior art keywords
carbon
decarburization
steel
layer
thickness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910865995.0A
Other languages
Chinese (zh)
Other versions
CN110648421A (en
Inventor
陈银莉
韦贺
胡磊
麻晗
米振莉
陈焕德
苏岚
孙志威
吴家明
宋勇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Science and Technology Beijing USTB
Jiangsu Shagang Group Co Ltd
Original Assignee
University of Science and Technology Beijing USTB
Jiangsu Shagang Group Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Science and Technology Beijing USTB, Jiangsu Shagang Group Co Ltd filed Critical University of Science and Technology Beijing USTB
Priority to CN201910865995.0A priority Critical patent/CN110648421B/en
Publication of CN110648421A publication Critical patent/CN110648421A/en
Application granted granted Critical
Publication of CN110648421B publication Critical patent/CN110648421B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C3/00—Registering or indicating the condition or the working of machines or other apparatus, other than vehicles
    • G07C3/005—Registering or indicating the condition or the working of machines or other apparatus, other than vehicles during manufacturing process
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02—Extraction of non-metals
    • C21D3/04—Decarburising
    • G—PHYSICS
    • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
    • G16C—COMPUTATIONAL CHEMISTRY; CHEMOINFORMATICS; COMPUTATIONAL MATERIALS SCIENCE
    • G16C20/00—Chemoinformatics, i.e. ICT specially adapted for the handling of physicochemical or structural data of chemical particles, elements, compounds or mixtures
    • G16C20/10—Analysis or design of chemical reactions, syntheses or processes
    • G—PHYSICS
    • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
    • G16C—COMPUTATIONAL CHEMISTRY; CHEMOINFORMATICS; COMPUTATIONAL MATERIALS SCIENCE
    • G16C60/00—Computational materials science, i.e. ICT specially adapted for investigating the physical or chemical properties of materials or phenomena associated with their design, synthesis, processing, characterisation or utilisation

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Computing Systems (AREA)
  • Theoretical Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Bioinformatics & Computational Biology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Analytical Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Abstract

The invention provides a method for calculating the thickness of a decarburized layer on the surface of decarburized spring steel, and belongs to the technical field of high-speed wire steel rolling. The method comprises the steps of firstly, calculating the theoretical equilibrium carbon concentration of the surface of a steel piece under different decarburization atmosphere conditions; then, under the conditions of different heating temperatures and heating time, the carbon content in the decarburization layer and the diffusion coefficient of carbon in ferrite are calculated; and finally, calculating the thickness of the decarburized layer on the surface of the steel part according to a decarburizing model calculation formula and by combining Gaussian error function analysis. The online prediction of the thickness of the decarburized layer in the hot continuous rolling process can be carried out in real time through the furnace atmosphere parameters, the temperature parameters and the time parameters in the real-time database of the hot rolling production line, and the hot rolling process parameters are adjusted according to the online prediction, so that the purposes of reducing the thickness of the decarburized layer and improving the surface quality of the spring steel are achieved.

Description

Method for calculating thickness of decarburized layer on surface of decarburized spring steel
Technical Field
The invention relates to the technical field of high-speed wire steel rolling, in particular to a method for calculating the thickness of a decarburized layer on the surface of decarburized spring steel.
Background
Spring steel is widely applied to the fields of various machines, instruments, traffic, petrochemical industry and the like. Along with the increasingly harsh working conditions of the spring steel, the requirements on the surface quality of the spring steel are also increasingly strict. In the hot continuous rolling process of the spring steel bar wire, the control of the thickness of the surface decarburized layer is one of surface quality control key technologies, the real-time monitoring of the thickness change of the surface decarburized layer is realized, and the control of the surface quality is the basis. Therefore, the exploration of the precise evolution law of the thickness of the decarburized layer of the spring steel in the hot continuous rolling process and different atmosphere environments is more and more important.
At present, researches on the thickness of the decarburized layer of the steel part mostly focus on the aspect of off-line measurement, and a metallographic method is mainly adopted. Further, chinese patent CN108195331A discloses a method for obtaining the thickness of a decarburized layer on a steel surface, which comprises pressing a steel material to be measured with a press head, and measuring the thickness of the decarburized layer according to the variation of the pressing speed. At present, the research on the thickness of the decarburized layer of the steel piece in the hot continuous rolling process reaching the online soft measurement through theoretical calculation is very little.
The invention realizes the technology of regulating and controlling the thickness of the surface layer decarburized layer of the spring steel in real time by applying an on-line prediction calculation method in the hot continuous rolling process, and has important influence on the development of reducing the production cost and producing high-surface-quality spring steel bar wires.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for calculating the thickness of a decarburized layer on the surface of decarburized spring steel, which combines real-time data of furnace atmosphere, heating temperature and heating time in the actual process of hot continuous rolling as input parameters to realize real-time prediction of the thickness change of the decarburized layer, thereby achieving the purposes of adjusting process parameters to control the thickness of the decarburized layer and improving the surface quality of a spring steel rod wire rod, and providing a new development direction for the high-quality surface layer processing technology of the rod wire rod.
The method comprises the following steps:
(1) determining the equilibrium carbon concentration according to the furnace atmosphere:
spring steel in decarburization atmosphere H2O、CO2、O2And H2The content of (A) is varied with the decarburization reaction, and the equilibrium carbon concentration C is sets0 to 0.01;
(2) determining the carbon content in the decarburization layer and the diffusion coefficient of carbon in ferrite:
the carbon content C of the spring steel in the decarburization layer is calculated according to the following formula:
Figure GDA0002743473600000021
wherein C is the carbon content in the decarburization layer,%; c0Original carbon content in steel,%; t is the holding time, s; d is the diffusion coefficient of carbon in ferrite, m2S; d is the thickness of the decarburized layer, m;
the diffusion coefficient D of carbon in ferrite is calculated as follows:
Figure GDA0002743473600000022
wherein D is0Is a diffusion constant, m2S; q is the diffusion activation energy, J/mol; r is a gas constant, J/(mol. K); t is absolute temperature, K;
(3) establishing spring steel decarburization measurement models at different heat preservation temperatures and different heat preservation times, and determining the thickness of the surface decarburized layer:
calculating the theoretical equilibrium carbon concentration C of the surface of the steel part under the condition of different furnace gas component partial pressures by utilizing the method in the step (1)s(ii) a Calculating the carbon content C in the decarburized layer in the steel and the diffusion coefficient of carbon in ferrite at different temperatures according to the method in the step (2)D。
The spring steel decarburization model calculation formula at different heating temperatures, different heating times and different furnace atmospheres is as follows:
Figure GDA0002743473600000023
wherein d is the thickness of the decarburized layer in the steel. According to the formula and the combination of the Gaussian error function, the evolution rule of the thickness d of the decarburized layer in the steel can be obtained.
Wherein, the chemical reaction equation of the decarburization in the step (1) is as follows:
ax+[C]＝by+cz
wherein a, b and c are coefficients of a chemical equation, x is a reaction participating gas, and y and z are production gases.
In the step (1), the equilibrium carbon concentration is related to the carbon activity of the surface of the spring steel, and the calculation formula of the carbon activity of the surface of the spring steel is as follows:
Figure GDA0002743473600000031
wherein, acIs the activity of carbon in austenitized steel; kPAs an equilibrium constant, when the temperature is constant KPIs a constant; px、Py、PzRespectively representing the partial pressure,%, of each component of the furnace gas; csatA saturated carbon concentration of austenite, when the temperature is constant, CsatIs constant,%; csThe carbon content in the steel surface and the furnace gas in balance determines the decarburization degree and speed of the steel surface layer.
As can be seen from the above formula, the different furnace gas component partial pressures determine the theoretical equilibrium carbon concentration C on the surface of the steel members. If the furnace gas continuously flows and the decarbonization reaction product is continuously taken away in the actual production process, the reaction is continuously shifted to the right, and the equilibrium carbon concentration C can be adjustedsSetting the value to 0-0.01.
Under the condition of variable temperature, the thickness of the decarburization layer in the steel can be decomposed into a plurality of tiny isothermal units to calculate the generation sum, and at this time, the calculation model formula of the thickness of the decarburization layer in the step (3) is as follows:
Figure GDA0002743473600000032
Figure GDA0002743473600000033
wherein, CiRepresents the carbon content,%, in the decarburization layer at time i; csiRepresents the content of carbon,%, at time i when the steel surface and the furnace gas are in equilibrium; diDenotes the diffusion coefficient of carbon in ferrite, cm at time i2/s；tiRepresents the time step at time i, s; diShowing time i, constant temperature TiA thickening of the decarburisation layer thickness, mm, wherein i ═ 1, 2, 3, … N; t isiRepresents the decarburization temperature at time i, K; c0Representing the original content of carbon in the steel.
The technical scheme of the invention has the following beneficial effects:
according to the scheme, the thickness of the surface decarburized layer can be predicted in real time, the method has the advantages of being simple and fast, and the method has important significance for actual production of an enterprise site.
Drawings
FIG. 1 is a schematic view of a model for controlling the thickness of a decarburized layer on the surface of a steel member on line at an enterprise production site according to the method for calculating the thickness of a decarburized layer on the surface of a decarburized spring steel of the present invention;
FIG. 2 is a graph showing the total decarburization layer thickness of 55SiCr type spring steel hot-rolled in an air atmosphere at 1000 ℃ on site in the example of the invention.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
The invention provides a method for calculating the thickness of a decarburized layer on the surface of decarburized spring steel.
As shown in fig. 1, the method comprises the steps of:
(1) determining the equilibrium carbon concentration according to the furnace atmosphere:
spring steel in decarburization atmosphere H2O、CO2、O2And H2The content of (A) is varied with the decarburization reaction, and the equilibrium carbon concentration C is sets0 to 0.01;
(2) determining the carbon content in the decarburization layer and the diffusion coefficient of carbon in ferrite:
the carbon content C of the spring steel in the decarburization layer is calculated according to the following formula:
Figure GDA0002743473600000042
wherein C is the carbon content in the decarburization layer,%; c0Original carbon content in steel,%; t is the holding time, s; d is the diffusion coefficient of carbon in ferrite, m2S; d is the thickness of the decarburized layer, m;
the diffusion coefficient D of carbon in ferrite is calculated as follows:
Figure GDA0002743473600000041
wherein D is0Is a diffusion constant, m2S; q is the diffusion activation energy, J/mol; r is a gas constant, J/(mol. K); t is absolute temperature, K;
(3) establishing spring steel decarburization measurement models at different heat preservation temperatures and different heat preservation times, and determining the thickness of the surface decarburized layer:
the spring steel decarburization model calculation formula at different heating temperatures, different heating times and different furnace atmospheres is as follows:
Figure GDA0002743473600000051
wherein d is the thickness of the decarburized layer in the steel.
The following description is given with reference to specific examples.
Example 1
In the embodiment of the invention, 55SiCr type spring steel is adopted,
Figure GDA0002743473600000054
and (3) wire rods.
The model for calculating the thickness of the decarburized layer on the surface of the hot continuous rolling 55SiCr type spring steel comprises the following steps:
taking the case of heating at 1000 ℃ for 60min in an air atmosphere, for example, when the carbon concentration is reduced to 85% as the starting point of the semi-decarburization, the decarburized layer depth of the 55SiCr spring steel is the distance from the surface of the structure containing 85% carbon in the steel.
Step 1: under the condition of air atmosphere, the main decarburization chemical reaction equation of the 55SiCr spring steel surface layer is as follows:
Figure GDA0002743473600000052
theoretical equilibrium carbon concentration C on 55SiCr spring steel surfaces：
Cs＝Csat·ac＝1.55×0.24＝0.37％
Step 2: the carbon content of the 55SiCr spring steel in the decarburization layer is as follows:
C＝C0×85％＝0.0055×0.85＝0.47％
the diffusion coefficient of carbon in ferrite at the heating temperature of 1000 ℃ is as follows:
Figure GDA0002743473600000053
and step 3: establishing a 55SiCr spring steel decarburization measurement model under the conditions of heat preservation temperature of 1000 ℃ and heat preservation time of 3600s, and determining the thickness of a surface decarburized layer:
calculating the theoretical equilibrium carbon concentration C of the surface of the 55SiCr steel piece under the air atmosphere condition by utilizing the method described in the step 1s(ii) a And (3) calculating the carbon content C in the decarburized layer and the diffusion coefficient D of carbon in ferrite in the 55SiCr steel at 1000 ℃.
The decarburization model calculation formula of 55SiCr spring steel under the conditions of the holding temperature of 1000 ℃, the holding time of 3600s and the air atmosphere is as follows:
Figure GDA0002743473600000061
from the gaussian error function:
d＝0.372(mm)
the total decarburized layer thickness of 55SiCr type spring steel hot-rolled in an air atmosphere at 1000 ℃ in situ is shown in FIG. 2.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (1)

1. A method for calculating the thickness of a decarburized layer on the surface of decarburized spring steel is characterized by comprising the following steps of: the method comprises the following steps:
(1) determining the equilibrium carbon concentration according to the furnace atmosphere:
spring steel in decarburization atmosphere H2O、CO2、O2And H2The content of (A) is varied with the decarburization reaction, and the equilibrium carbon concentration C is sets0 to 0.01;
(2) determining the carbon content in the decarburization layer and the diffusion coefficient of carbon in ferrite:
the carbon content C of the spring steel in the decarburization layer is calculated according to the following formula:
Figure FDA0002743473590000011
wherein C is the carbon content in the decarburization layer,%; c0Is the original carbon content in the steel,%; t is the holding time, s; d is the diffusion coefficient of carbon in ferrite, m2S; d is the thickness of the decarburized layer, m;
the diffusion coefficient D of carbon in ferrite is calculated as follows:
Figure FDA0002743473590000012
wherein D is0Is a diffusion constant, m2S; q is the diffusion activation energy, J/mol; r is a gas constant, J/(mol. K); t is absolute temperature, K;
(3) establishing spring steel decarburization measurement models at different heat preservation temperatures and different heat preservation times, and determining the thickness of the surface decarburized layer:
the spring steel decarburization model calculation formula at different heating temperatures, different heating times and different furnace atmospheres is as follows:
Figure FDA0002743473590000013
wherein d is the thickness of the decarburized layer in the steel;
the equilibrium carbon concentration in the step (1) is related to the carbon activity of the surface of the spring steel, and the calculation formula of the carbon activity of the surface of the spring steel is as follows:
Figure FDA0002743473590000014
wherein, acIs the activity of carbon in austenitized steel; kPAs an equilibrium constant, when the temperature is constant KPIs a constant; px、Py、PzRespectively representing the partial pressure,%, of each component of the furnace gas; csatA saturated carbon concentration of austenite, when the temperature is constant, CsatIs constant,%; csThe content of carbon in the steel surface and the furnace gas in balance determines the decarburization degree and speed of the steel surface layer;
under the condition of variable temperature, the calculation model formula of the thickness of the decarburized layer in the step (3) is as follows:
Figure FDA0002743473590000021
Figure FDA0002743473590000022
wherein, CiRepresents the carbon content,%, in the decarburization layer at time i; csiRepresents the content of carbon,%, at time i when the steel surface and the furnace gas are in equilibrium; diDenotes the diffusion coefficient of carbon in ferrite, cm at time i2/s；tiRepresents the time step at time i, s; diShowing time i, constant temperature TiA thickening of the decarburisation layer thickness, mm, wherein i ═ 1, 2, 3, … N; t isiRepresents the decarburization temperature at time i, K; c0Represents the original content of carbon in the steel;
the chemical reaction equation of decarburization in the step (1) is as follows:
ax+[C]＝by+cz
wherein a, b and c are coefficients of a chemical equation, x is a reaction participating gas, and y and z are production gases.
CN201910865995.0A 2019-09-12 2019-09-12 Method for calculating thickness of decarburized layer on surface of decarburized spring steel Active CN110648421B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910865995.0A CN110648421B (en) 2019-09-12 2019-09-12 Method for calculating thickness of decarburized layer on surface of decarburized spring steel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910865995.0A CN110648421B (en) 2019-09-12 2019-09-12 Method for calculating thickness of decarburized layer on surface of decarburized spring steel

Publications (2)

Publication Number Publication Date
CN110648421A CN110648421A (en) 2020-01-03
CN110648421B true CN110648421B (en) 2020-12-29

Family

ID=68991310

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910865995.0A Active CN110648421B (en) 2019-09-12 2019-09-12 Method for calculating thickness of decarburized layer on surface of decarburized spring steel

Country Status (1)

Country Link
CN (1) CN110648421B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115132298B (en) * 2021-03-29 2024-10-18 宝山钢铁股份有限公司 Spring steel decarburization analysis prediction method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1212022A (en) * 1996-11-20 1999-03-24 新日本制铁株式会社 Method of vacuum decarburization refining of molten steel and apparatus therefor
CN106399867A (en) * 2016-09-28 2017-02-15 睿智钢业有限公司 Processing technology for super-strength corrosion-resistant steel product and rolling unit thereof
EP3476953A1 (en) * 2016-10-24 2019-05-01 JFE Steel Corporation Electric resistance welded steel pipe for high-strength thin hollow stabilizer and manufacturing method therefor

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002285233A (en) * 2001-03-23 2002-10-03 Sanyo Special Steel Co Ltd Method for producing forged ring material for cold rolling forming
CN101879530B (en) * 2010-06-25 2013-03-13 东北大学 Soft measurement method of thickness of scale on surface of hot continuous rolling strip steel
CN103045826A (en) * 2013-01-01 2013-04-17 首钢总公司 Test method for simulating oxidation and decarbonization of steel
CN108396128A (en) * 2017-11-28 2018-08-14 江苏省沙钢钢铁研究院有限公司 Control method for surface decarburization of bloom alloy tool steel wire
CN110172555B (en) * 2019-06-27 2020-12-25 上海交通大学 Decarburization process for improving hydrogen embrittlement resistance of steel surface layer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1212022A (en) * 1996-11-20 1999-03-24 新日本制铁株式会社 Method of vacuum decarburization refining of molten steel and apparatus therefor
CN106399867A (en) * 2016-09-28 2017-02-15 睿智钢业有限公司 Processing technology for super-strength corrosion-resistant steel product and rolling unit thereof
EP3476953A1 (en) * 2016-10-24 2019-05-01 JFE Steel Corporation Electric resistance welded steel pipe for high-strength thin hollow stabilizer and manufacturing method therefor

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Effect of H2O(g) on Decarburization of 55SiCr Spring Steel During the Heating Process;Kai ZHANG, Yinli CHEN, Yanhui SUN, Zhijun XU;《Acta Metall Sin》;20181031;1350-1358 *
Surface Decarburization Behavior of Spring Steel 60Si2MnA under AC1 Temperature and in Temperature Range AC3-G;Zhao F , Zhang C , Xiu Q , et al.;《Materials ence Forum》;20150831;132-136 *

Also Published As

Publication number Publication date
CN110648421A (en) 2020-01-03

Similar Documents

Publication Publication Date Title
KR100847974B1 (en) Method of controlling material quality on rolling, forging or straightening line, and apparatus therefor
CN110245382B (en) Method for determining Avrami mathematical model coefficient of metal dynamic recrystallization volume fraction
CN101879530B (en) Soft measurement method of thickness of scale on surface of hot continuous rolling strip steel
CN110648421B (en) Method for calculating thickness of decarburized layer on surface of decarburized spring steel
CN112651562B (en) Laser cladding process optimization method based on signal-to-noise ratio and improved gray correlation degree
Bo et al. Static recrystallization kinetics model after hot deformation of low-alloy steel Q345B
Bouhieda et al. Selective Oxidation of Chromium by O 2 Impurities in CO 2 During Initial Stages of Oxidation
CN111118269A (en) Method for regulating and controlling microstructure of ultrasonic rolling surface layer
KR102655059B1 (en) Surface hardening treatment device and surface hardening treatment method
CN112597627A (en) Calculation method for predicting thickness of oxide layer in spring steel heating process
CN111157567B (en) Method for measuring volume ratio of two-phase transformation of low-alloy high-strength steel during continuous cooling
CN103774085B (en) A kind of high-nitrogen austenitic layer in the preparation of low-carbon alloy steel surface and preparation method
KR102075245B1 (en) Prediction apparatus for iron loss reduction of electric steel sheet
CN112711822A (en) Industrial gas pipe network modeling method based on dynamic identification
CN115374617A (en) Method for calculating carbon concentration field in spring steel square billet heating process
Keddam et al. Simulation of the growth kinetics of γ′-nitride layers on Armco iron by the integral method
Arif et al. Effect of process variables on gas nitriding of H13 tool steel with controlled nitriding potential
Lu et al. Estimation of screw’s physical properties using neural network
CN107783559A (en) A kind of new controllable oxidization process control method
CN116694903B (en) Self-adaptive adjustment method and system for annealing copper pipe
KR20220057601A (en) Surface hardening treatment device and surface hardening treatment method
CN113109165A (en) Double-phase steel continuous annealing and galvanizing thermal simulation experiment method and device
CN1022053C (en) Dynamic controllable nitriding technology under optimal diffusion condition
JPH0753287B2 (en) Method for cold rolling metastable austenitic stainless steel
JPS5896866A (en) Controlling method for quantity of carburization in vaccum carburization treatment

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant