The semifinished product of camshaft of Leng Jizhu iron that casts stable qualification

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Camshaft of material of Leng Jizhu iron has good wearability, but craft applicability is poor, this affected its application in car market on certain level. And pass reasonable control its chemistry composition, undertake molding sand is controlled, the semifinished product of camshaft of Leng Jizhu iron that can acquire stable qualification. The material of camshaft basically can be divided character for Leng Jizhu iron, steel qualitative, alloy cast iron (but temper by dipping in water is mixed forcedly inferior arc remelting) , nodular cast iron, combined-type. Circumstance of the craft sex of the camshaft with all sorts of qualitative material, weight, wear, market application each are not identical (detailed sees a table) . Camshaft of material of Leng Jizhu iron has good wearability, be applied in great quantities by car market gradually, but its craft applicability is poor, this affected its further progress on certain level. In actual production, the element such as the control that be pregnant with of the molten iron before the control of the chemical component of material, molding sand, process temperature control, furnace and ball turn, mould and technology design is met affect Leng Jizhu the craft of iron camshaft uses a sex. From chemistry component and molding sand control this two respects to talk about the influence that cast-iron to Lengji camshaft casts below. Chemical composition 1, the main factor that appropriate carbolic equivalent decides function of Leng Jizhu iron is: The function of the amount of the cold carbide that stimulate a layer and configuration and black lead amount and metallic matrix. When carbolic equivalent (CE=C+1/3Si) taller when form Leng Ji layer easily, and the carbide quantity in Leng Ji layer increases, this taller to obtaining cold hardness that stimulate a layer is very advantageous; But organization of aggravation of configuration of the addition that also brings black lead amount at the same time, black lead, matrix becomes bulky wait for adverse effect. Become especially condition of be pregnant with bad or existence minim is harmful when the element, bulky black lead makes metallic matrix can bear the valid area of load decreases, make the intensity of metallic matrix cannot be developed normally, reduce cast-iron intensity thereby. Graph 1: The pearlite in matrix is in cast-iron material, pearlite has better strength and hardness, and ferrite is softer, intensity is inferior also. As amount of C, Si rise, can make pearlite amount decreases (see a picture 1) , configuration becomes more bulky, at the same time ferrite amount increases (see a picture 2) , these metropolises reduce the tensile strength of material. Accordingly, in ensure after obtaining enough Leng Ji layer, should be in carbolic equivalent control an inferior level, in order to acquire taller product machinery property. But, when carbolic equivalent is too low, besides go against the Leng Ji that has obtained beyond the layer, still can increase shrinkage cavity liability, cause a product to discard as useless (see a picture 3) . So, in fusion process, controlling carbolic equivalent is a when solve function of material of camshaft of Leng Jizhu iron very main factor. Through practice, the author thinks to be worth CE control to be in 3.

9~4.

2 it is more appropriate normally. Graph 2: More ferrite is contained in matrix 2, alloying element is to the influence of material function in camshaft of Leng Jizhu iron, commonly used alloying element basically has Cr, Cu, Ni, Mo to wait, these elements are in the action in molten iron each are not identical. The main effect of Cr is the formation that promotes white mouth, form compound carbide with C, Fe, in order to raise the hardness of Leng Ji layer and wearability. But, the in adding initiate to make be not Leng Ji area carbide of Cr estimates increase, make material brittleness increases, the amount of ferrite decreases to disappear even. In the meantime, as a result of the affiliation of alloying element, also refined black lead on certain level, and among them ferrite gets solid dissolve aggrandizement as a result of the alloying element that has certain amount, make cast-iron have taller intensity property. Graph 3: A.

(CE<3.

9) core shrinkage cavity 3, the effect that charging compounds to compare pair of data goes we think to want requirement of chemical composition up to specification only all the time, should can obtain the data that accords with standard machine function, what actually place of this kind of viewpoint sees is groovy and chemical composition only, and oversight a few microelement and the effect that harmful element amid has. If cast iron is the main source of Ti, because this cast iron makes the how many meeting of dosage affects the content of the Ti in material directly, produce very big effect to the mechanical function of material; Useless steel is the origin of a lot of alloying element, because this abandons steel dosage,the influence of cast-iron to Lengji mechanical function is very direct. Accordingly, the mechanical performance that charging matchs to compare cast-iron to Lengji data is having immediate effect, it is fusion pilot stress. Additional, to reduce the charging transmissibility effect to material, proposal charging part of one's job approves management, accomplish first-in first-out. Graph 3: B.

(CE>4.

2) core shrinks the molding sand performance with good control of loose molding sand is the requirement that produces an eligible semifinished product, this kind of viewpoint is in now be accepted by more and more manufacturer home place. Because producing Leng Jizhu,the need in the process of iron camshaft puts many Leng Tie, these cold iron are removing model, have a change of luck and Central Africa of process closing case to often drop easily, and cold iron surface goes against exhaust, and condense easily lunt, the molding sand that reason place needs should be spent in wet intensity of pressure, the respect such as water portion, permeability undertakes be controllinged strictly. And the molding sand function that wants to gain good stability, should have the following requirements at least: The first, have a complete sand preparation system and an online testing system; The 2nd, what should choose function to stabilize as far as possible is former complementary material; The 3rd, mix arenaceous parameter and Yuan Fucai makings reasonably to deserve to compare certainly; The 4th, there is one to cover the program that has analytic dogging to molding sand function on management. Graph 4: Molding sand graph includes to the analytic trace program of molding sand function: 1, the collection of data the data that the data that the spot detects and molding sand detect should undertake collection by formulary form, cannot regard the standard that judges molding sand stand or fall as these data merely, use the analysis, quality trend that forecasts future however. 2, the processing of data, analysis wants regular person specially assigned for a task or job to use current and advanced statistic to analyse a tool to undertake an analysis to collection data, find out the rule, according to characteristic pilot requirement, undertake early-warning to potential unqualified factor, so that take step in time, will potential unqualified factor tries to eliminate. 3, dog to should undertake dogging detecting recording to taking the molding sand quality after measure, teach acquisition experience a lesson reservation to come down, provide a basis for in the future improvement. The semifinished product of camshaft of Leng Jizhu iron that brief summary wants to obtain stable qualification, trying to control to chemical composition, molding sand not allow to ignore. Pass the CE cost that controls good molten iron, according to metallographic organization and material performance demand adjust the content of good alloy, notice the control to microelement at the same time, with respect to the chemical component that can control good molten iron; Want to establish a scientific hierarchy of control to the control of molding sand, such ability assure the stability of molding sand, satisfy the requirement that produces camshaft of Leng Jizhu iron. Additional, the control of the other element such as the control that plus opposite Cheng temperature be pregnant with of the molten iron before control, furnace and ball turn, mould and technology design, the Lengji that can produce a stable qualification certainly is cast-iron camshaft semifinished product. CNC Milling CNC Machining