CN1128245C - High-strength alloyed cast steel with high resistance to wear and impact and its preparing process - Google Patents

Abstract

The present invention discloses high-strength alloyed cast steel with high strength and wear resistance and a productive technology thereof. The high-strength alloyed cast steel takes C, Si, Mn and Cr as main elements to be additionally added with a small amount of elements, such as Mo and V, and Fe as the rest. The structures of the cast steel are austenite with uniform fine grains after being processed with the productive technology of the present invention, and a small quantity of tiny diffusing type carbides are positioned between intracrystalline parts and crystal boundaries. The high-strength alloyed cast steel exists high intensity and impact resistant toughness; compared with the existing high manganese steel ZGMn13-4, the intensity of the high-strength alloyed cast steel is increased by 24%, and the impact resistant toughness is increased by 56.5%. The austenite on the working surface is changed into high hardness martensite (HRC is at least 69) after being sharply impacted and worn; the service life of the cast steel is more than 2.8 times of that of products imported to China; the price is 35% of that of the average imported price. The present invention has wide practical and popularizing value.

Description

The impact-resistant alloy cast steel of a kind of high intensity wear-resistant and manufacturing process

Technical field

The invention belongs to metal material field, relate generally to the industries such as mine, metallurgy, building materials, electric power, machinery, rock drilling, ordnance, it is that a kind of being widely used in is manufactured under strong collision impact and the strong wear condition and the novel alloy cast steel of long parts of its intensity height of job requirement, good toughness, wear-resistant, non-cracking, life-span. The invention still further relates to the manufacturing process of the impact-resistant alloy cast steel of a kind of high intensity wear-resistant.

Technical background

Though in the prior art field be anti-in low strong wear or the anti-high-wearing alloy cast steel that surpasses in the explosive severe impact of impacting, ubiquity easy fracture, not wear-resisting, the life-span short, change the phenomenon frequent, that cost is high. It is one always and be badly in need of solves and the end Technological Economy difficult problem that can fundamentally comprehensively thoroughly solve all the time for many years.

Cause the reason of the above results many and complicated, because change procedure broken, that grind in the operating mode is a physical change process that relates to the factors complexity, it needs many-sided subject knowledge such as mechanics, kinematics, Metal Material Science, heat treatment and the abundant practical experience just possible solving practical problems that combines. But still lack at present these complicated applications operating modes are done comprehensive, scientifical concrete analysis, more lack actual Journal of Sex Research that the science preparation of the metal material that satisfies these special operation condition requirements, composition is combined with reasonable, economic Technology for Heating Processing and to the accurate instruction in application market, this is the major reason that causes the above results.

For example: in deep layer drilling well rock drilling, its rock stratum hardness of zones of different is different, even same rock well, different depth, its formation hardness is also different, thereby so that the suffered rock drilling power of bit of rock drilling machine and the degree of wear change with the rock well depth. So should adopt the drill bit of different performance to different well layer hardness. And the rotational oscillation impact that Selecting for Liner of Cement Mill Machine bears and wearing and tearing be by its main abrasive body steel ball that is installed in and by the weight of mill body material, hardness and mill speed common the decision. Under same operating, the impact that lining board of grinder bears and wearing and tearing are cyclically-varying in the grinding machine rotation. Because being that arc is board-like, liner plate and grinding mill barrel wall be fixedly connected, and synchronous rotational speed is not high, so hardness and wearability to liner plate are selected very important, it is high that the hardness ratio material hardness of main abrasive body steel ball is wanted, and it is lower than liner plate hardness, otherwise not only can have influence on cement output and quality, but also can greatly reduce liner plate service life.

The grinder hammerhead of High Rotation Speed particularly carries out the heavy-duty crusher tup of large-scale production, they in shattering process because the be broken size of material, shape, weight, hardness all are irregular variations, cause size, direction, application point and the suffered degree of wear temporal evolution of its suffered impact and recoil strength and sharply change, thus increased widely grinder hammerhead or bar can satisfy fully wear-resisting, shock-resistant, the ratio of reduction is large, percentage of damage is high, broken output high, the technical difficulty of long service life.

At present domestic for reaching wear-resistant shock-resistant purpose, different according to applicable cases, the employing wear resistant cast iron that has; High strength martensitic or the austenitic stainless steel of the employing costliness that has; The employing 45# steel that has or low-alloy steel forging, modified through integral body, its operate portions bit table is quenched; More then be to adopt potassium steel.

Now chemical analysis, mechanical performance, metallographic structure and the applicable working condition with them is listed as follows:

About the domestic at present statistical form of the main relevant composition of wear and shock-resistant material that adopts, performance, tissue, purposes

The domestic at present chemical analysis (%) of main wear-resisting, the high impact material that adopts in table (1)-1

(standard No.) material trademark	Chemical analysis (%)
										C	Si	Mn	Cr	Mo(V)	Ni	Cu(W)	S	P
	(GB8263-87) KmTBCr9Ni5Si2 (wear resistant cast iron)	2.5-3.6	1.5-2.2	0.3-0.8	8-10	0-1.0	4.5-6.5		≤0.1										≤0.15
(GB8263-87)   KmTBCr20Mo 2Cu 1(wear resistant cast iron)										2.0-3.0	≤1.0	0.5-1.0	18-22	1.5-2.5	0-1.5	0.8-1.2(Cu)	≤0.06	≤0.1
	(GB6967-86) ZG06Cr13Ni6Mo (high strength martensitic stainless steel)	0.06	1.0	1.0	11.5-13.5	0.4-1.0   0.03(V)	5-6.5	0.5(Cu)   0.1(W)	0.03										0.035
(GB2100-80) ZG1Cr18Mn8Ni4N (austenitic stainless steel)										≤0.1	≤1.5	7.5-10	17-19		3.5-5.5	0.12-0.25(N)	≤0.03	≤0.03
	(GB5680-85) ZGMn13-1 (antiwear high manganese steel)	1.1-1.5	0.3-1.0	11-14					≤0.05										≤0.09
(GB5680-85) ZGMn13-4 (shock-resistant potassium steel)										0.9-1.2	0.3-0.8	11-14					≤0.05	≤0.07
	(GB3077-88) 20CrMo (chrome-moly steel)	0.17-0.24	0.17-0.37	0.4-0.7	0.8-1.1	0.15-0.25	≤0.3		≤0.025										0.025

Table (1)-2 domestic at present performance, tissue and the purposes of main wear-resisting, the high impact material that adopts

(standard No.) material trademark	Mechanical performance				Explanation
						Б b(N/mm 2)	δ	α kv	HB
	(GB8263-87) KmTBCr9Ni5Si2 (wear resistant cast iron)	≥520		25J/cm 2   (α kv)						≥522   HRC＝55	Eutectic carbide [(Cr, Fe)7C 3+(Fe、Cr) 3C]+proeutectoid carbide+martensite+retained austenite; Firmly, wear-resisting, but intensity, toughness are poor.
(GB8263-87)   KnTBCr20Mo 2Cu 1(wear resistant cast iron)					≥539		19J/cm 2   (α kv)	≥550   HRC＝58	Be eutectic carbide (Fe, Cr)7C 3+ proeutectoid carbide+martensite+retained austenite; The intensity toughness is poor though wearability is good.
	(GB6967-86) ZG06Cr13Ni6Mo (high strength martensitic stainless steel)	＞745	15％	59J/cm 2   (α kv)						221-286	Be martensite, intensity still can, but the shock resistance firmware is low, the low wear resistant applications of impacting in being suitable for.
(GB2100-80) ZG1Cr18Mn8Ni4N (austenitic stainless steel)					588	40％	147J/cm 2	≤207	1100 ℃ of-1150 ℃ of shrends inside are austenite, surface martensite (HRC 〉=45), the wear resistant applications of moderate low impact.
	(GB5680-85) ZGMn13-1 (antiwear high manganese steel)	637	20％	147J/cm 2						≤229	Water is tough to be treated to even austenite, and the surface is hit and is transformed into martensite after the wearing and tearing; The wear resistant applications of moderate low impact; Such as liner plate etc.
(GB5680-85) ZGMn13-4 (shock-resistant potassium steel)					735	35％	147J/cm 2	≤229	The tough processing of water is even austenite afterwards, and working surface is hit, and is transformed into martensite after the wearing and tearing, and its strength and toughness is medium, available medium impact, wearing and tearing occasion.
	(GB3077-88) 20CrMo (chrome-moly steel)	883	12％	98J/cm 2						≤197	Modified is sorbite, working face table HRC＞50 after the lonneal of quenching, degree of depth 4-8mm; Can be used for medium and small impact and wear working condition, such as medium and small tup etc.

Obvious from table Plays or practical data result: though the antifriction alloy white cast-iron has very high hardness and shows good wearability, its toughness and tensile strength are very low, obviously can not be as the selection of material of thump and sharp wear occasion; Two kinds of antifriction alloy white cast-iron contain noble element (Cr, Mo, Ni) total amount respectively up to 17.5%, 26%; Cause undoubtedly its production cost to increase severely; For reducing the weight error of wear resistance castings, realize self momentum balance of the broken and wearing and tearing of High Rotation Speed, annealing softening heat treatment before this wearing piece must be processed again, must quench again and tempering heat treatment for improving its comprehensive mechanical performance after to be processed, so just further increase the production cost of this wear part. With regard to purposes, it is little that it can only make load, and the wearing piece of low microshock is because its cost is high, so it will lose use value. High strength (martensite and austenite) stainless steel, though higher tensile strength is arranged, its hardness and toughness are still lower, can not satisfy thump and sharp worn occasion; Again because of the content summation of its precious metal element (Cr, Mo, Ni, V and Mn etc.) respectively up to 22.11%, 34.75%; Add the heat treatment expense, it is really uneconomical to make wear-resisting, the impact-resistant tup etc. of middle grade with this bi-material undoubtedly.

China has formulated the standard of GB5680-86 to potassium steel, and is not harsh with regard to standard, but the most enterprises of China all can not produce complete standard compliant potassium steel; The potassium steel that the enterprise that also has produces has been covered with pore, burning into sand even crackle. Metallographic structure is even austenitic potassium steel after the tough processing of water even meet the requirements fully, because its working surface austenite structure only is transformed into the martensite of high rigidity just now under the impact of q.s, anti-damage, reaches wear-resisting purpose. So under collision impact and the comparatively mild working condition that weares and teares, potassium steel shows seriously wearability deficiency; And but it shows the deficiency of serious intensity, toughness and often fracture under severe impact large, heavy, the firmly collision fragmentation of thing and strong wear.

Adopt the low-alloy steel forging, after modified, preferably comprehensive mechanical performance is arranged, also fair to the working face table rear hardness of quenching; But depth of hardening zone is more shallow, needs again annealing after being worn, preheating repair welding, tempering; Again process again, show to quench and whole lonneal, so its expense is very high; Its toughness is not high yet in addition; So it can only be suitable for the operating mode occasion of medium impact and wearing and tearing.

For satisfying wear-resisting, impact-resistant Technological Economy requirement in the reality production, the technology and equipment of the producer's Introduced From Abroad that has, the external product component of direct purchase that has. The existing enterprise that domestic and international technology and equipment is more advanced, with their best wear-resisting, shock-resistant material manufacturings the product that can represent material property---the main conditions of grinder hammerhead are listed as follows:

Performance, the price statistics one hurdle table table (2) of at present domestic and international major vendor manufacturing tup

Manufacturer	Main Mechanical	The product valency (yuan/ton)	Remarks
				Tangshan Cement Machinery Factory	Б b＝588N/mm 2  α k＝60J/cm 2	22000	Tup is potassium steel series
Shanghai Heavy Machinery Plant	Б b＝696N/mm 2  α k＝100J/cm 2  HB＝220-240	16000	Voluntarily development
				Beijing Heavy-duty Machine Factory	Б b＝883N/mm 2  α k＝54J/cm 2δ 〉=12% ψ 〉=40% HB=230-250 (modified integral body) HB=410-460 (table quench working position)	29600	Introduce Denmark's technology
Denmark, Japan, Australia	Б b＝765-804N/mm 2 α k＝170J-190J/cm 2 HB＝220-240	Contain tariff, freight and miscellaneous charges 65000-120000	Their import tup is adopted in the cement plant, Liuzhou.

It seems that from general status present domestic employing is wear-resisting, the grinder hammerhead of high impact material manufacturing all belongs to general light-duty tup, the weight of tup own is between 8kg～50kg; So only be used for general small-scale production, the broken raw meal particle size of institute is little and softer, as: the low microshock of malachite, lime stone, glass etc. Owing to successively often generation of fracture in using, cause many producers to need stopping production remove to change the fracture tup up to 5～6 times in one month on the whole generally at 1～3 month its service life.

The steel alloy tup that Beijing Heavy-duty Machine Factory introduce technology to make from Denmark, not only price is high, and comprehensive mechanical performance is unsatisfactory, and its operating period, broken material was unusual also only has 3～5 months according to institute. Wear and shock-resistant material product---the tup of Denmark, Australia, Japan has successively been bought in the cement plant, Liuzhou when introducing Denmark's disintegrating apparatus. It is expensive: 6.5 ten thousand yuan～120,000 yuan (containing tariff, freight charges); Its operating period, rubble output was 90～1,100,000 tons in the cycle also only at 8～10 months. Its wear-resisting and toughness still can not satisfy production requirement fully.

Through the retrieval Chinese patent, find two patents, its patent No. and proprietary term are respectively: 95118510 (a kind of middle manganese austenite abrasion-resistant cast steels); 96119545 (a kind of abrasion resistant cast steels). The chemical analysis of now the two being claimed, performance data philosophy are listed as follows: table (3)-1

Proprietary term	Chemical analysis (%)
												C	Si	Mn	Cr	Mo	Ti	V	B	RE	P	S
	(95118510) a kind of middle manganese austenite abrasion-resistant cast steel	0.75-1.0	0.4-0.7	7-8.5	1.2-1.5	0.9-1.2				0.02-0.  04	≤0.06												≤0.04
(96119545) a kind of abrasion resistant cast steel												0.15-0.3 5	≤0.5	≤1.0	1.5-2.0	0.2-0.5	0.05-0.10	0.05-0.1 0	0.005-  0.10	0.1-0.5	≤0.0.4	≤0.04
	0.35-0.5 0	≤0.50	≤1.0	1.0-1.5	0.2-0.5	0.02-0.05	0.02-0.0 5	0.005-  0.10	0.05～0.  10	≤0.04	≤0.04

Table (3)-2

Proprietary term	Main Mechanical				Heat treatment mode	Metallographic structure
							Б b	δ	α k	HB
	(95118510) a kind of middle manganese austenite abrasion-resistant cast steel	421-569N/ mm 2	7.5％-11.0 ％	30-40 J/cm 2							230-260	The tough processing of water	Austenite+a small amount of carbide; Working surface is that shape becomes martensite.
(96119545) a kind of abrasion resistant cast steel					1245-1382 N/mm 2	6.3％-10％	82-96 J/cm 2	HRC＝45 -54	880 ℃-890 ℃ insulations 2 hours are heated to 2-3 hour water-cooled again of 220 ℃-230 ℃ insulations after the shrend. Be suitable for the thump wear working condition.	Martensite+bainite+a small amount of retained austenite.
	Behind 2-3 hour oil quenching of 860 ℃-870 ℃ insulations, be heated to 2-3 hour water-cooled of 220 ℃-230 ℃ insulations. Be suitable for medium and small impact wear operating mode.

Through repeatedly studying 95118510 patents of invention carefully, recognize that being intended that of inventor solves potassium steel and can not be transformed into rapidly martensitic structure at the austenite of its working surface under non-intense impact and wearing and tearing of the single austenite structure after the tough processing of water, its case hardness and wearability present not good enough state defective; The content that the inventor passes through to reduce C, Mn in the potassium steel is to improve Ms, Md transition temperature, and additional Cr, Mo are to improve permeability; Add again a small amount of rare earth elements RE and reduce the P in the steel, the content of S with purify hot metal, and the flowability of increase molten steel improves its casting character; So that the middle manganese wear-resistant steel that the inventor claims obtains single-phase unstable austenite structure after the tough processing of water, under non-intense impact repeatedly, wearing and tearing, bring out a large amount of strain-induced martensite tissues because of the unstable austenite of flow on its surface; And the reinforcement of strain-induced martensite is far above stacking staggered floor and the interactive sclerosis mode of solid solution element of potassium steel, thereby improves the wearability under non-thump state of wear, to reduce the purpose of manufacturing cost and use cost; And claim that its two example is improved 1～1.5 times effect in service life than common potassium steel.

Through repeatedly studying 95118510 patents of invention in full, illustrate that this patented invention condition is still immature, and lack the reasons are as follows of actual use value:

(1) the significant data index of display material shock resistance in this medium managese steel: tensile strength

(Б _b＝441N/mm ²) and toughness (α_k＝30～40J/cm ²) well below domestic common potassium steel ZGM13-4 (Б_b＝735N/mm ³，α _k＝147J/cm ²); And the initial surface hardness (HB=230～250) that determines material wear ability is close with common potassium steel hardness (HB=230).

(2) with regard to the element assembly, the high-load of the Mn of this manganese steel, Cr, Mo alloying element always is 11.2%; And only contain Mn11～14% in the potassium steel, obviously in the close manganese steel of these two kinds of alloy total contents, be to be higher than potassium steel by raw material cost and the expense of smelting of the medium managese steel of multiple precious alloy element assembly, and increased multicomponent alloy difficulty and expense to detection and the control of the accurate content of each element in smelting.

(3) its enforcement result data shows: the adding of rare earth elements RE does not make P, S content reduce; Make people have the effect of purify hot metal to feel confused to RE here; The reduction of C, Mn; Cr, Mo's is additional, does not only improve the comprehensive mechanical performance of medium managese steel, and it compares but greatly inferior with common potassium steel.

In sum, since this claim wear-resisting Austenitic Medium Manganese Steel compare with common potassium steel except the initial hardness of working surface quite, all other mechanical performances are all much lower, so make people be improved 1～1.5 times practice in service life to its comparing with common potassium steel of claiming and effect is doubted.

If the medium managese steel property indices is true described in this patent of invention, it is little that it only can make broken wearing and tearing granularity so, the lining board of grinder of the low impact of light weight that rotating speed is not high; But its intensity, wearability can be well below cheap and good-quality 20CrMo in the table (1).

Patent 96119545 inventors claim to be by a kind of by Mn, Cr, Mo, Ti, V (except C, the Si) is polynary and be Minor element, additional micro-B, RE element (the highest total content of alloying element is 3.7%), through smelt, after the casting again through a kind of high strength, high rigidity, metallographic structure that twice heat treatment is obtained be tempered martensite+bainite+a small amount of retained austenite (in) steel alloy, with the collision impact that is implemented in medium and small energy and wear and tear lower have enough intensity and toughness, the potassium steel that remedies single austenite structure can not be rapidly be transformed into the martensite of high rigidity and not wear-resisting by work hardening, the defective that service life is short at the lower austenite of medium and small impact and abrasive conditions lower surface initial hardness.

Chemical analysis under two kinds of application states recommending from this invention and the effect data analysis of three application examples, this abrasion-resistant stee has very high intensity: Б b (tensile strength)=1245-1382N/mm²； Б _s(yield strength)=1196-1206N/mm², while hardness is high (HB=427～513, HRC=45～54) also; But its toughness is relatively poor, ballistic work A_kBe 65.8～76.5J only, be equivalent to α_k＝(82～96J/cm ²), but its hardness is much lower than wear resistant cast iron hardness (HB=522～551, HRC=55～58).

So patent of invention 96119545 (a kind of abrasion resistant cast steel) may not satisfy large when carrying out large-scale production, heavy, the broken high rotating speed of hard material, large momentum, its action and reaction power surpass explosive severe impact and the high-wearing work condition state that changes. Press the flexibility of the metallographic structure of metal material and mechanical performance and the relation of rigidity, passing through a tempering, (δ=6.3%～9.85% under whole high rigidity (HB=427-513), low stretch rate and the low-shrinkage is obtained in twice cooling, and toughness still has medium value (82～95J/cm ψ=12.4～21.6%),²), its tensile strength is unexpectedly up to 1236N/mm²More than, really puzzling!

Certain such as performance data as described in this patent, it can be used for making under the humble impact conditions take anti-wear performance as main lining board of grinder etc. undoubtedly.

Summary of the invention

The purpose of this invention is to provide the impact-resistant alloy cast steel of a kind of high intensity wear-resistant, fully satisfied the requirement that severe impact and high-wearing operating mode are used, long service life, cost is low.

Another object of the present invention provides the manufacturing process of the impact-resistant alloy cast steel of a kind of high intensity wear-resistant of the present invention.

In order to achieve the above object, the present invention adopts following technical measures: its technical characterictic is take C, Mn, Cr as essential element, additional a small amount of Mo, V element; After implementing manufacturing process provided by the present invention, its microscopic structure is even austenite to this cast steel again, and a small amount of small diffuse type carbide is arranged between its intracrystalline and crystal boundary; This steel has very high intensity and toughness; After being subjected to severe impact, its working surface austenite is transformed into rapidly the martensite of high rigidity (HRC=68～71), thereby it has again good wearability. Under anti-severe impact and strong wear condition, up to the present the good comprehensive mechanical performance that shows, also still finds no both at home and abroad than its better material existence. The chemical analysis weight percent content of cast steel of the present invention sees the following form: the chemical analysis of cast steel of the present invention (%) table (4)

Chemical element	C	Si	Mn	Cr	Mo	V	P	S	Fe
										Content	0.85-1.25	0.45-0.75	10-12.5	1-2	0.15-0.4	0.035-0.095	≤0.035	≤0.035	82.935-  87.515

Carbon among the present invention (C) some is that solid solution is in the one of the chief elements of austenitic manganese steel alloy. In addition, C also with solid solution each unnecessary alloying element in austenite all with the primary carbide of lattice complexity: Fe₃C、VC、Mo ₂C、Cr ₇C ₃、Mn ₇C ₃Deng and regeneration (Fe.Cr)₃C、(Cr.Fe) ₇C ₃、(Cr.Fe) ₂₃C ₆、 (Mo.Fe) ₂₃C ₆Exist etc. multiple carbide form, thereby improved intensity, hardness and the wearability of steel alloy; The maximum level that is dissolved in the solid solution of γ-Fe formation austenite because of C is 2%. For making its grain size of austenite after the tough processing of water the thinnest: grain size≤20 μ m², its phosphorus content can fix on 0.8%～1.3%, if C content is too high, its toughness is descended, and is easy to fracture, because a small amount of decarburization possibility is arranged in smelting or the heat treatment, so phosphorus content is controlled in 0.85%～1.25% scope among the present invention.

Manganese (Mn) is the Main Ingredients and Appearance of austenitic manganese steel alloy, a part of Mn except solid solution in austenite and reduced austenite to martensitic transition temperature Ms, and deformation brings out austenite and is transformed into martensitic temperature Md, thereby increased the stability of overcooling austenite; Make C curve to the right with to moving down, reduced critical cooling rate, thereby improved quenching degree, can make the very large workpiece in cross section obtain the metallographic structure of uniformity, and another partly is present in (Fe.Mn)₃C、Mn ₇In the carbide such as C, intensity and impact flexibility have greatly been improved; Mn energy and impurity S formation MnS remove certainly with the molten slag form in addition, so Mn has the function of purify hot metal and automatic impurity removing. The content of Mn is controlled at 10%～12.5%, after the tough processing of water, obtain more stable single austenite structure, its working surface impacted and wear and tear after can be transformed into rapidly the martensitic structure of high rigidity, thereby improve widely its hardness and wearability.

Silicon (Si), silicon is often allocated into deoxidier, and its content is≤0.8% the time, and all solid solutions are in austenite and improve significantly the intensity of austenitic steel. Silicon all has no significant effect growing up and austenite being begun to be transformed into martensitic temperature Ms of austenite crystal; A little less than Si forms carbide in austenitic steel ability than Fe is, so Si does not form carbide. But Si can significantly improve temper resistance, and silicon can improve the flowability of molten steel, to improve its castability, so silicone content is controlled at 0.45%～0.75% among the present invention.

Alloying element chromium (Cr) and their somes of molybdenum (Mo) are dissolved in the austenite, increase the stability of overcooling austenite, and C curve is moved to right, and have reduced critical cooling rate, thereby all can improve the quenching degree of steel; And another part of Cr, Mo element all is dissolved in cementite (Fe₃C) in, with trickle, disperse, fill the air, stable alloy carbide: (Fe.Cr)₃C、(Fe.Mo) ₃C、(Cr.Fe) ₂₃C ₆、(Mo.Fe) ₂₃C ₆Deng state be present in the austenite grain boundary and crystal boundary between, except the obstruction Austenite Grain Growth, and refine austenite crystal grain and improve intensity, hardness and the wearability of steel significantly; During Cr constituent content≤5%, the intensity of steel and hardness increase with the increase of chrome content, but the toughness of steel is when chrome content≤1%, are that the increase with its content increases to 323J/cm² When chrome content 1%≤x≤3%, its toughness is by 323J/cm²Drop to 269.5J/cm² When its toughness of chrome content＞3% sharply descends. So chrome content is defined as 1%～2% among the present invention; During Mo constituent content≤7%, the intensity of steel and hardness increase with the increase that contains the Mo amount, but the toughness of steel with the increase that contains the Mo amount by 245J/cm²Sharply drop to 68.6J/cm², particularly when molybdenum (Mo) amount of containing＞0.4% in the steel, its toughness descends remarkable especially; So the content of Mo should be controlled between 0.15%～0.4%.

Vanadium (V), V in austenitic alloy steel with disperse, in the crystal boundary that vanadium carbide (VC) state tiny and extreme hardness (HRC=71-75) is present in overcooling austenite and hamper consumingly growing up of austenite crystal between crystal boundary; When V content is 0.04%～0.1%, austenitic temperature is during at 912 ℃～960 ℃, its austenite crystal changes very little. Therefore, the working surface that the allocating into of V can be improved austenitic alloy steel significantly impact and wearing and tearing under and the metallographic structure of the strain-induced martensite that produces makes the lens lamellar martensite finer and closely woven; Undoubtedly, it greatly improves intensity, hardness and the wearability of steel; Be the hardness of raising strain-induced martensite and intensity and the tough of wearability and overcooling austenite, the content of V is defined as 0.035%～0.095%.

Phosphorus (P) solid solution has the tendency that increases Austenite Grain Growth after in austenite; Steel plasticity and toughness is at normal temperatures descended, and has and promote C, Mn element to produce the tendency of segregation, thus among the present invention the content of P be defined as≤0.035%.

Sulphur (S) exists with the form of FeS and MnS in austenitic steel. MnS enters molten slag, and low-melting eutectic but FeS and Fe can survive is distributed on the crystal boundary, has weakened adhesion between crystal boundary, and steel, is very easily broken when stressed hot. Among the present invention the content of S be controlled at≤0.035% scope in.

The impact-resistant alloy cast steel of a kind of high strength and high hardness of the present invention adopts electric arc furnace smelting; By 2: 1 pulverized limestones with fluoridize the powder slag making; Steelmaking feed is steel scrap and ferroalloy; The furnace charge addition sequence is: steel scrap, ferrochrome and foundry returns; Wait melting rear adding ferromanganese, molybdenum-iron; Add Si at reduction period, utilize Mn, Si to carry out just deoxidation; Add again vanadium iron; Add amphoteric oxide aluminium (Al) 1kg by molten steel per ton before the casting and carry out final deoxidation treatment, tapping temperature is: 1500 ℃～1510 ℃, its chemical analysis of affirmation to be detected meets requirement of the present invention, can cast when molten steel temperature is 1460 ℃～1480 ℃. Its concrete production technology is as follows:

1. the casting of blank: tapping temperature is 1500 ℃～1510 ℃, cast temperature is 1460 ℃～1480 ℃, foundry goods should be unpacked at 270 ℃～310 ℃, should carry out immediately sand removal and the work of cutting dead head after unpacking, and casting temperature should be 250 ℃～280 ℃ during the cutting dead head.

2. to the processing of casting defect: as: spilehole, shallow surface check, burning into sand etc., after 250 ℃～300 ℃ polishings of band temperature are removed, can adopt 107 (A107) welding rod difficult to understand, DC welder carries out repair welding, adopt in the lump the high speed grinding wheel sander to polish flat together with overlap, burr, spatter, or again advance stove and be preheated to about 280 ℃～310 ℃, carry out above-mentioned mill, benefit work.

3. annealing in process: the blank after will leveling advances stove and is heated to 650 ℃～680 ℃, is incubated 6～8 hours and cools off with stove.

4. machining: use YW₂Cutter, the employing per second mills or car less than 2.5 meters low speed, or the mode of planing, processes by drawing.

5. the tough processing of water: partly become product to be heated to 600 ℃～620 ℃ insulations 2～3 hours the steel-casting that processes, then that furnace temperature is of continuing rising to 870 ℃～890 ℃ and be incubated 2～4 hours, be heated to again 1040 ℃～1060 ℃, be incubated 4～6 hours; It is that fast cooling processing is carried out continuously in the quick circulation pond of 10～12 times of cast steel weight that last quick tapping places the water purification amount with steel-casting.

The impact-resistant alloy cast steel of a kind of high-strength abrasion-proof of the present invention is homogeneous austenite structure under normal temperature after the tough processing of water, in its crystal boundary and between crystal boundary a small amount of small diffusivity carbide is arranged; Austenite mechanical performance under its normal temperature is: Б_b≥912N/mm ²，6≥45.8％，α _k＝224～238J/cm ², HB=234～249. Under severe impact and wearing and tearing, the austenite of its working surface is transformed into rapidly the martensite of high rigidity (HRC=66～71), thereby has increased widely its wearability.

The impact-resistant alloy cast steel of a kind of high-strength abrasion-proof of the present invention improved its metallographic structure and processing characteristics widely after annealing in process, broken the legend that austenite abrasion-proof steel for many years can not be processed; Satisfied simultaneously the Equilibrium of main broken body in large momentum, the broken wearing and tearing of High Rotation Speed.

The present invention in one's power the impact-resistant steel alloy of a kind of high-strength abrasion-proof under severe impact and strong abrasive conditions, compare with World Developed Countries, its intensity improves 16%, toughness improves 28.3%, improve more than 2.8 times (Japan, West Germany, Sweden are 8～September, and this product is also to use continuing in 36 months) friction durability; And price only is 46%～25% of import price. The product that it and domestic technique equipment advanced person's enterprise makes is compared, and its impact flexibility north is brought up again high 3.28 times; Bring up again high 1.31 times; Improve 2.85 times than the Tang Shui machine; Intensity is brought up again on high by 30.4%, improves 54.3% than the Tang Shui machine. And the product price suitable (about 30000 yuan/tons) that the heavy Introducing Technical Equipment in product price and north is made. It has solved comprehensively, up hill and dale fundamentally that the industries such as mine, metallurgy, building materials, electric power, machinery, rock drilling, ordnance long-standing various alloy cast steel easy fractures, intensity under severe impact and strong wear condition are low, not wear-resisting, the life-span short, it is frequent to change, manufacturing or the high economic technology difficult problem of use cost.

(120000 yuan/tons are amounted to: 14458 dollars/T), life cycle was with 10 months, the whole nation in one's power enterprise is 700 calculating by Liuzhou cement import Sweden, Belgian mug(unit of measure) company product price; So, can be country in 10 months saves foreign exchange: 3542.168 ten thousand dollars; If export 20000 tons, and by existing import lowest price decline 30%, then can be 9.1 hundred million yuans of country's wound output values every year; Amounting to dollar is: 1.0964 hundred million yuan.

Therefore, it has extensive practical value and promotional value, and can obtain the remarkable performance of enterprises and economic results in society.

The specific embodiment

The present invention now provide three examples according to composition prescription of the present invention and manufacturing process for further explaining, implementation technique is as follows:

1. join the stove melting by chemical analysis of the present invention, treat molten steel temperature at 1500 ℃, and composition is qualified after testing, slag to be removed is cast during at 1480 ℃ when temperature; When foundry goods is chilled to 290 ℃,

Unpacking sand removal; Cutting dead head temperature is 270 ℃.

2. to inspection and the processing of casting defect: through checking that carefully foundry goods is fully qualified more than 92%, only have a small amount of cast(ing) surface that local 3-5 spilehole of dispersion bare cloth arranged, after the polishing of recycling high speed grinding wheel was clean, band temperature (T=254 ℃) was carried out repair welding, and welding rod is A107; Weld seam is continuous, full, smooth.

3. annealing in process: the blank after will leveling advances stove and is heated to 660 ℃, is incubated 6 hours and cools off with stove.

4. machining: use YW₂Cutter adopts per second less than the mode of 2.5 meters low-speed vehicle, processes by drawing.

5. the tough processing of water: the steel-casting semi-finished product that process are heated to 610 ℃, are incubated 2 hours, then that furnace temperature is of continuing rising to 880 ℃, and be incubated 3 hours, and be heated to again 1050 ℃, be incubated 6 hours; It is that fast cooling processing is carried out continuously in the quick circulation pond of 10～12 times of cast steel weight that last quick tapping places the water purification amount with steel-casting. More than be the concrete steps of embodiment 1, example 2,3 duplicates. Concrete chemical analysis and mechanical performance, purposes and the effect list of three examples are as follows:

Embodiment	Chemical analysis (%)									The austenite mechanical performance			Working surface martensite hardness (HRC)	Range of application and effect
															C	Si	Mn	Cr	Mo	V	P	S	Fe	Б b	α k	HB
	％	％	％	％	％	％	％	％	％	N/mm 2	J/cm 2
															1	0.99	0.45	11.38	1.64	0.18	0.037	0.027	0.012	85.284	906	224	234-239	66-69	Produce 500 tons of-600 ton large-scale jaw crusher tups (135kg/ spare) when being used for; On November 2nd, 1998 is not fracture so far.
2	1.05	0.54	12.05	1.85	0.21	0.035	0.032	0.02	84.213	930	230	242-245	68-71	Produce 500 tons of-600 tons of jaw crusher tups (135kg/ spare) when being used for; On September 4th, 2000 is not fracture so far.
															3	0.87	0.64	10.87	1.98	0.37	0.065	0.029	0.011	85.165	918	238	243-249	68-71	Produce 240 tons of Φ 1250mm * 125mm board hammer of impact crushers (153kg/ spare) when being used for; On December 2nd, 2000 is not bad so far.

Claims (2)

1. impact-resistant alloy cast steel of high intensity wear-resistant, its assembly element wt percentage is:

C：0.85～1.25；  Si：0.45～0.75；  Mn：10～12.5；  Cr：1～2；

Mo：0.15～0.4；  V：0.035～0.095； P：≤0.035；    S：≤0.035；

Fe：82.935～87.515。

2. manufacturing process that realizes the impact-resistant alloy cast steel of high intensity wear-resistant of claim 1, it comprises the following steps:

(1) casting of blank, tapping temperature are 1500 ℃～1510 ℃, and cast temperature is 1460 ℃～1480 ℃, and foundry goods is unpacked the sand removal temperature at 270 ℃～310 ℃, and cutting dead head temperature is 250 ℃～280 ℃;

(2) to the processing of casting defect, after 250 ℃～300 ℃ polishings of band temperature are removed, adopt the A107 welding rod to carry out repair welding, weld seam should be continuous, smooth, bright and clean;

(3) annealing in process is advanced stove with the blank after leveling and is heated to 650 ℃～680 ℃, is incubated 6～8 hours and cools off with stove;

(4) machining is used YW₂Cutter, the employing per second mills or car less than 2.5 meters low speed, or the mode of planing is processed;

(5) the tough processing of water, the steel-casting semi-finished product that process are heated to 600 ℃～620 ℃, be incubated 2～3 hours, then furnace temperature is of continuing rising to 870 ℃～890 ℃ and be incubated 2～4 hours, be heated to 1040 ℃～1060 ℃ insulations 4～6 hours, coming out of the stove steel-casting is placed the water purification amount is that continuous cooling processing is carried out in the circulation pond of 10～12 times of cast steel weight again.