Stainless steel fusion has characteristic and appropriate control skill is very nervous

Stainless steel of nitrogen of ZG1Cr17Mn12Ni2N chromic manganese is stainless steel of a kind of Gao Ge, tall manganese, tall nitrogen, low nickel austenite, metallographic construction is onefold austenite, it is to be able to bear or endure corrupt stainless steel, its are mechanical performance is very high. Because of its peculiar physics character, generating electricity having in the industry very special road of other external use.

Study the whole course that produces through opposite holds elucidate, control originally, admit AC+LF+VOD fusion, got high strenth, low electric conduction, low guide ray of magnetism, X detects passing cast material.

1. Material character

Because nitrogen is violent austenite,change an element, be in " Cr-Mn-N " in fastening stainless steel, WN ＝ 0.015% when, the metallographic construction of steel is ferrite; , 0.13% ～ of WN ＝ 0.33% when, the metallographic construction of steel is ferrite and austenite; WN ＝ 0.58% when, attainable onefold austenite.
But in actual production, rigorous to steel contains azotic quantity mediumly to answer control, because be in same normally below fusion condition, of nitrogen attend a quantity to override when affirmative life looks, because azotic separate out reachs the separate out that hydrogen promoted when azotic separate out, make cast produces aperture of do sth in a fit of pique and loose limitation easily.
Can low nitrogen is in the element such as the Cr in steel, Mn, Mo the activity in steel, ascensive nitrogen dissolves mediumly in steel competence, and Ni, Si, C can wash out nitrogen the solubility in steel. Nitrogen is in the Xi Hua of solubility comply with in steel is especially mensurable, suck nitrogen to suffer Xihuate to decide law demarcate from inside gas phase, the fusion skill that accords with in order to be necessary, yuan Ling drives the azotic content that like making be in, normally pressure condition plays thermodynamic balanced the azotic content when, so that nitrogen the circumstances consist in with clearance atom or nitride in steel.
Because carbon forms carbide in steel, to austenite stainless steel be able to bear or endure corrupt function harm is great, use up in order to be C probably low, because this appropriate controls WC ＝ 0.12% ～ 0.15% .
Chromium is to make stainless steel has the essential element that fights corrupt ability, when WCr ＞ 12% when, of steel fight corrupt function to produce mutation, because this should control WCr ＝ 16.5% ～ 17.75% .
Nickel is the element that stimulative austenite forms, have fight corrupt ability excellently, and it is precious alloy metal, "Cr-Mn-N " department stainless steel is to fall into disuse of nickel enter an amount, save capital, but attend a few collective and other element uses nickel, can progress the integral performance of steel.
Manganese also is austenite forms an element, can the branch replaces nickel use, at the same time of manganese attend also benefit at nitrogen deliquescent, not the place of apply is low steel be able to bear or endure corrupt sex, because this should control WNi ＝ 11% ～ 12.5% .

The place on put together is narrated, good constructs to onefold austenite, in fusion course, after attending right amount manganese and chromium, attend nitrogen with the circumstances of nitride again.

2. Chemical identity is controlled

(1) demand of ZG1Cr17Mn12Ni2N chemical capacity

(2) to assure the solid dissolve of the nitrogen in steel fluid reachs the integral performance with excellent cast, of steel fluid inside accuse chemical identity to press a watch 2 trees model is surrounded hold control.

3. Fusion course is controlled

(1) electric arc furnace operates admit return law fusion, use high grade useless steel, in order to ensure the phosphorous content of steel fluid does not exceed bid. Tall carbon ferrochrome and low carbon ferrochrome are spread at hearth, the content of frit clear carbon of steel fluid presses WC ＝ 1.5~1.7% control. Oxidation period blows oxygen decarbonization to WC ＝ 0.6~0.7% , after the event of oxidation period complete gathers up clean slag, attend metallic manganese, ferrosilicon, silicon calcium piece, aluminium piece hold precipitation to oxigenate.
Chromic content presses upper limit control, nickel content is pressed in upper limit control. Low carbon ferromanganese and metallic manganese attend after slag is contented and reductive, manganese content overrides ＝ of WC of norms upper limit 0.5% .
New broken bits is built afresh after deoxidizing stage blocking stage sheds broken bits to operate, hold desulphurization to operate, diffuse deoxidizer admits carbolic pink, silicon calcic pink and aluminium powder, should accomplish reductive and contented. Reach through changing broken bits to operate those who enrich is reductive, take off sulfur content to WC ＝ 0.015% the following. Gather up the tapping after broken bits, temperature of tapping of electric arc furnace is 1700~1720 ℃ .
(2) LF ＋ VOD is pithy operate coal tub enters LF to be versed in hind new slagging, and power transmission warms up, hold reductive to decoke to operate. Desulphurization comes sulfur content ＜ 0.01% , warm up to 1660~1680 ℃ hind, condole bag comes gather up broken bits platform is held gather up broken bits operates.
Gather up bag of the condole after broken bits enters VOD to be versed in into coal tub, vacuum is held to blow oxygen decarbonization to operate after vacuumize, the pressure that blow oxygen is 0.9~1.0MPa, check after occurrence inflection point of oxygen chroma appearance blow oxygen, successive vacuumize holds vacuum carbon to oxigenate to operate, next concatenate 10~15min are spent in 133Pa vacuum.
Slagging material and deoxidizer attend after broken vacuum, successive vacuumize holds vacuum reductive, next concatenate 15~20min are spent in 133Pa vacuum.
Reductive complete after the event attends vacuum nitrogen changes what ferrochrome holds nitrogen to match, the azotic content that consider wants to have to molten steel Central Plains when matching nitrogen is 0.015% the left and right sides, hold fine tuning to chemical identity, calcic iron line is fed to hold after temperature of chemical identity, molten steel is accorded with eventually deoxidization.
Identity pass mark, temperature accords with a condole the bag is pouring. The wall of credential cast is large, plan through melting point reach the degree of superheat that accord with, in order to be delimit pouring temperature is 1555~1565 ℃ more appropriate.

5. Epilogue

Pass contented skill and manufacturing preparation, smelt gave passing, high grade ZG1Cr17Mn12Ni2N chromium the steel fluid of manganese nitrogen stainless steel, the happy production that become the ground gave passing cast, satisfactory the client's demand. Got the craft parameter of stainless steel of nitrogen of ZG1Cr17Mn12Ni2N chromic manganese at the same time, mastered essentials of fusion of this kind of steel, for me the company produces this kind of steel to plant later hit a copy kept as a record, increased the manufacturing scope of my company at the same time.

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