Summary of the invention
The first object of the present invention is: for above-mentioned prior art Problems existing, provide a kind of alloy wrought steel, this alloy wrought steel is easy to manufacture, comprehensive mechanical property is excellent, is particularly useful for manufacturing bullet train or EMUs retarding disc.
The first object of the present invention is achieved through the following technical solutions: a kind of alloy wrought steel, its each component and mass percent as follows: carbon 0.26% ~ 0.35%; Silicon 0.15% ~ 0.39%; Manganese 0.85% ~ 1.50%; Phosphorus is less than or equal to 0.02%; Sulphur is less than or equal to 0.01%; Chromium 0.80% ~ 2.00%; Nickel 0.70% ~ 2.00%; Molybdenum 0.35% ~ 1.00%; Surplus is iron and other elements, and the mass percent summation of other elements described is less than or equal to 0.30%.
In technique scheme, preferably, described manganese is 0.85% ~ 1.19%; Further preferably, described manganese is 0.85% ~ 1.10%.
In technique scheme, preferably, described chromium is 0.91% ~ 2.00%; Further preferably, described chromium is 0.91% ~ 1.95%; Again further preferably, described chromium is 0.91% ~ 1.85%.
In technique scheme, preferably, described nickel is 0.71% ~ 2.00%; Preferred again, described nickel is 0.71% ~ 1.64%; Further preferably, described nickel is 0.71% ~ 1.61%; Further preferred, described nickel is 0.72% ~ 1.61%.
In technique scheme, preferably, described molybdenum is 0.35% ~ 0.70%; Further preferably, described molybdenum is 0.38% ~ 0.63%; Again further preferably, described molybdenum is 0.38% ~ 0.49%.
In technique scheme, preferably, described silicon is 0.20% ~ 0.39%; Further preferably, described silicon is 0.22% ~ 0.34%.
In technique scheme, preferably, the content of described phosphorus is for being less than or equal to 0.019%; Preferably, the content of described sulphur is for being less than or equal to 0.009%.
In technique scheme, preferably, other elements described comprise oxygen, hydrogen, nitrogen, and wherein oxygen mass percentage content is less than or equal to 0.0020%; Hydrogen mass percentage content is less than or equal to 0.0005%; Nitrogen mass percentage content is less than or equal to 0.0070%.
In other elements described, except the harmful alloying elements that should control that some are common, as tin, antimony, arsenic, copper etc.; Can also be comprised some to the alloying element of the beneficial properties of steel as one or more in the elements such as vanadium, titanium, tungsten, niobium.
In technique scheme, preferably, other elements described comprise any one or any two in vanadium, titanium, tungsten, niobium element and more than; Its content is vanadium≤0.1%, titanium≤0.08%, tungsten≤0.04%, niobium≤0.05%.
In technique scheme, further preferably, other elements described comprise any one or any two in vanadium, titanium, tungsten, niobium element and more than; Its content is vanadium < 0.1%, titanium≤0.08%, tungsten≤0.04%, niobium≤0.05%.
In technique scheme, the metallographic structure after described alloy wrought steel modifier treatment is sorbite tissue.
Alloy wrought steel of the present invention can adopt LF+VOD+VD of the prior art (ladle oven process+vacuum-oxygen decarbonizing oven process+vacuum decarburization oven process) process for smelting steel or similar process for making to be prepared.
Each chemical composition role and preferred content range thereof in forged steel is smelted once contained by alloy wrought steel of the present invention is described below in detail.
In steelmaking process, manganese is good reductor and sweetening agent.Even if when adding more than 0.70% in carbon steel " manganese steel ", the steel of more general manganese amount not only has enough toughness, and has higher intensity and hardness, improves the hardening capacity of steel, improves the hot workability of steel.In the present invention, its content is preferably controlled 0.85% ~ 1.19%; Preferably manganese is 0.85% ~ 1.10% further.
Chromium can improve the intensity of steel, hardness and wear resistance.Meanwhile, chromium can improve again the hot strength of steel, is the important alloying element of high temperature steel.In the present invention, preferably being controlled by its content at chromium is 0.91% ~ 2.00%, and further preferred chromium is 0.91% ~ 1.95%, and further preferred chromium is 0.91% ~ 1.85%.
Nickel expands the element of austenite phase field, and be also solution strengthening element, and along with the increase of nickel content, the normal temperature strength of steel and hot strength increase, and to plasticity and Toughness little, specifically can see Fig. 1, Fig. 2.In the present invention, preferably being controlled by its content at described nickel is 0.71% ~ 2.00%; Further preferred described nickel is 0.71% ~ 1.64%, more preferred nickel is 0.71% ~ 1.61% further; Further preferably nickel is 0.72% ~ 1.61%.
Molybdenum can make the grain refining of steel, improves hardening capacity and thermostrength, keeps enough intensity and creep resisting ability (be at high temperature subject to stress for a long time, deform, claim creep) when high temperature.Add molybdenum in steel, can mechanical property be improved; And the fragility that steel alloy can be suppressed to cause due to tempering.In the present invention, preferably being controlled by its content at molybdenum is 0.35% ~ 0.70%; Preferably molybdenum is 0.38% ~ 0.63% further; More preferably molybdenum 0.38% ~ 0.49% again.
In the present invention, controlled by silicon 0.15% ~ 0.39%, preferred silicon is 0.20% ~ 0.39%, and preferably silicon is 0.22% ~ 0.34% further.
In the present invention, phosphorus is controlled be less than or equal to 0.02%; Sulphur is less than or equal to 0.01%; Preferred phosphorus content is less than or equal to 0.019%; Preferred sulphur content is for being less than or equal to 0.009%.
In the present invention, preferred oxygen level is less than or equal to 0.0020%; Preferred hydrogen richness is less than or equal to 0.0005%; Preferred nitrogen content is less than or equal to 0.0070%.
The second object of the present invention is the application providing a kind of aforementioned alloy wrought steel, and described alloy wrought steel is applied to manufacture brake disc of high-speed train.
The second object of the present invention realizes by providing following a kind of brake disc of high-speed train: it uses aforesaid alloy wrought steel manufacture to form.
The third object of the present invention is to provide a kind of can improve mechanical property further, reduce the heat treating method of the aforementioned alloy wrought steel of distortion and crackle tendency.
The third object of the present invention is that it comprises the following steps by providing the heat treating method of aforementioned alloy wrought steel to realize:
First carry out normalizing treatment, after being warming up to 860 DEG C ~ 920 DEG C, be incubated 3 ~ 5 hours, air-cooled to normal temperature;
Then modifier treatment is carried out: be incubated 3 ~ 5 hours after first quench treatment is warming up to 860 DEG C ~ 920 DEG C, shrend; Carry out temper subsequently, be incubated 3 ~ 5 hours after being warming up to 550 ~ 620 DEG C, air-cooled or water-cooled is to normal temperature.
Preferably, in the heat treating method of alloy wrought steel, temperature-rise period when carrying out described normalizing treatment and quench treatment is, is incubated 1 ~ 2 hour, and then is warming up to 860 DEG C ~ 920 DEG C after being first warming up to 650 DEG C ~ 700 DEG C.
Preferably, in the heat treating method of alloy wrought steel, when carrying out described normalizing treatment and quench treatment, heat-up rate is 120 DEG C ~ 200 DEG C/h.
Beneficial effect of the present invention is mainly reflected in:
(1) choose reasonable to manganese, nickel, chromium, the multiple alloying constituent of molybdenum and collocation is passed through, while guarantee forged steel intensity increases, can also ensure that plasticity and the toughness of material are not subject to considerable influence, avoid the phenomenon because intensity increase causes material plasticity and toughness obviously to decline.Obtained alloy wrought steel material comprehensive mechanical property is excellent; Obviously overcome disc material of the prior art due to each mating chemical composition unreasonable and cause in intensity and the contradiction (referring to simultaneous test below) of moulding, can not take into account in toughness.
(2) by manganese, nickel, chromium, the multiple alloying constituent of molybdenum and and the rational proportion of the main chemical compositions such as carbon, silicon, improve hardening capacity and the thermostrength of alloy wrought steel material, and normal temperature strength and hot strength have also been obtained and increase substantially.
(3) by manganese, nickel, chromium, the multiple alloying constituent of molybdenum and and the rational proportion of other main chemical compositions such as carbon, silicon, the wear resistance of alloy wrought steel material of the present invention is better than prior art.The Brinell hardness number of alloy wrought steel material adopting technical solution of the present invention to obtain reaches 300 ~ 388HBW(and refers to simultaneous test below).
(5) alloy wrought steel material of the present invention is after suitable thermal treatment, grain refining, further increase the tensile strength of alloy wrought steel material, yield strength and toughness, hot strength and plasticity have also been obtained obvious improvement, distortion and crackle tendency little (referring to simultaneous test below).
(6) mechanical performance index that alloy wrought steel of the present invention is after heat treatment reached is as follows: tensile strength >=1070MPa; Yield strength >=905MPa; Unit elongation >=14%; Relative reduction in area >=35%; Brinell hardness number is 300 ~ 388HBW.The material requirements of 250Km/h and above brake disc of high-speed train can be met completely.
In addition, alloy wrought steel of the present invention adopts conventional LF+VOD+VD (ladle oven process+vacuum-oxygen decarbonizing oven process+vacuum decarburization oven process) process for smelting steel or similar process for making to be prepared, it is convenient to smelt, forging easily, manufacturing cost reduces, and is more conducive to industrialized enforcement and popularization.
On EMU, run-in test has been carried out with the EMU retarding disc of alloy wrought steel material of the present invention manufacture.Operation result shows, the EMU retarding disc steady quality, excellent performance, the long service life that manufacture with alloy wrought steel material of the present invention; Meanwhile, compared with same kind of products at abroad, also there is higher superiority of effectiveness.
Show in sum, choose reasonable and the proportioning of other main chemical compositions such as carbon, silicon in the alloying constituents such as manganese, chromium, nickel, molybdenum and forged steel material is passed through due to the present invention, after suitable thermal treatment, make grain refining, improve hardening capacity and the thermostrength of alloy wrought steel material, normal temperature strength and hot strength increase substantially, and obtained alloy wrought steel not only has higher tensile strength and yield strength, also have good performance moulding, in toughness, comprehensive mechanical property is excellent.Meanwhile, alloy wrought steel material of the present invention also has that wear resisting property is good, distortion and crackle tendency little, smelt convenient, forging easily and the low advantage of manufacturing cost, be conducive to the work-ing life and the industrial application that extend brake disc of high-speed train.
Embodiment
About addressing other technologies content, feature and effect before the present invention, in the detailed description of following embodiment, can clearly present.But those skilled in the art will recognize that specific descriptions that with reference to accompanying drawing are herein only for example object, the present invention is not limited thereto.
The chemical composition (%) of table 1 alloy wrought steel of the present invention
C |
Si |
Mn |
P |
S |
Ni |
Cr |
Mo |
0.26% ~ 0.35% |
0.15% ~ 0.39% |
0.85% ~ 1.50% |
≤0.020% |
≤0.010% |
0.70% ~ 2.00% |
0.80% ~ 2.00% |
0.35% ~ 1.00% |
As shown in table 1, each component and the mass percent scope thereof of alloy wrought steel of the present invention are as follows: carbon 0.26% ~ 0.35%; Silicon 0.15% ~ 0.39%; Manganese 0.85% ~ 1.50%; Phosphorus is less than or equal to 0.02%; Sulphur is less than or equal to 0.01%; Chromium 0.80% ~ 2.00%; Nickel 0.70% ~ 2.00%; Molybdenum 0.35% ~ 1.00%; Surplus is iron and other elements.
Other constituent contents described are less than or equal to 0.30%.Other elements described comprise oxygen, hydrogen, nitrogen, and wherein oxygen mass percentage content is less than or equal to 0.0020%; Hydrogen mass percentage content is less than or equal to 0.0005%; Nitrogen mass percentage content is less than or equal to 0.0070%.
Other elements described also comprise any one or any two in the elements such as vanadium, titanium, tungsten, niobium and more than.Its content is preferably vanadium≤0.1%, titanium≤0.08%, tungsten≤0.04%, niobium≤0.05%; More preferably, vanadium < 0.1%, titanium≤0.08%, tungsten≤0.04%, niobium≤0.05%.
Other elements in the application comprise two classes, and other elements of a class are harmful to the performance of steel under normal circumstances, as tin, antimony, arsenic, copper, hydrogen etc.; The performance of other elements another kind of to steel is useful, and as vanadium, titanium, tungsten, niobium etc., its content is generally vanadium≤0.1%, titanium≤0.08%, tungsten≤0.04%, niobium≤0.05%.
In other elements described, except the harmful alloying elements that should control that some are common, as tin, antimony, arsenic, copper etc.; Can also be comprised some to the alloying element of the beneficial properties of steel as a kind of or two kinds and the above combination in the elements such as vanadium, titanium, tungsten, niobium.
In alloy wrought steel composition of the present invention, in order to improve the performance of steel further, strictly should control the content of oxygen, hydrogen, nitrogen, preferred oxygen level is less than or equal to 0.0015%; Preferred hydrogen richness is less than or equal to 0.0003%; Preferred nitrogen content is less than or equal to 0.0060%.
The mechanical property that above-mentioned alloy wrought steel reaches is in table 2.
The mechanical property of table 2 alloy wrought steel of the present invention
Tensile strength |
Yield strength |
Unit elongation |
Relative reduction in area |
Brinell hardness number |
≥1070MPa |
≥905Mpa |
≥14% |
≥35% |
300 ~ 388HBW |
The Mechanics Performance Testing of alloy wrought steel of the present invention is by GB/T 228 metallic substance tensile testing at ambient temperature and GB/T 231.1 metal static hardness test part 1: test method is carried out.As seen from Table 2, alloy wrought steel of the present invention can meet the requirement of more than 250km/h brake disc of high-speed train to forged steel mechanical property completely.
In order to improve the performance of alloy wrought steel further, preferably, described manganese is 0.85% ~ 1.19%; Further preferably, described manganese is 0.85% ~ 1.10%.
Preferably, described chromium is 0.91% ~ 2.00%; Further preferably, described chromium is 0.91% ~ 1.95%; Again further preferably, described chromium is 0.91% ~ 1.85%.
Preferably, described nickel is 0.71% ~ 2.00%, and further preferably, described nickel is 0.71% ~ 1.64%; Again further preferably, described nickel is 0.71% ~ 1.61%; Further preferred, described nickel is 0.72% ~ 1.61%.
Preferably, described molybdenum is 0.35% ~ 0.70%; Further preferably, described molybdenum is 0.38% ~ 0.63%; Again further preferably, described molybdenum is 0.38% ~ 0.49%.
Preferably, described silicon is 0.20% ~ 0.39%; Further preferably, described silicon is 0.22% ~ 0.34%.
Preferably, the content of described phosphorus is for being less than or equal to 0.019%; Preferably, the content of described sulphur is for being less than or equal to 0.009%.
Preferably, oxygen level is less than or equal to 0.0020%; Hydrogen richness is less than or equal to 0.0005%; Nitrogen content is less than or equal to 0.0070%.
In a further preferred embodiment, the mass percent of each component of described alloy wrought steel is as follows:
Carbon 0.26% ~ 0.35%; Silicon 0.22% ~ 0.34%; Manganese 0.85% ~ 1.41%; Phosphorus is less than or equal to 0.019%; Sulphur is less than or equal to 0.009%; Chromium 0.91% ~ 1.85%; Nickel 0.72% ~ 1.61%; Molybdenum 0.38% ~ 0.63%; Surplus is iron and other elements; The content of other elements is less than or equal to 0.30%; Wherein, oxygen level is less than or equal to 0.0020%; Hydrogen richness is less than or equal to 0.0005%; Nitrogen content is less than or equal to 0.0070%.
In this preferred alloy wrought steel, preferred described manganese is 0.85% ~ 1.19%; Preferably manganese is 0.85% ~ 1.10% further again.
In this preferred alloy wrought steel, preferred described silicon is 0.20% ~ 0.39%, and preferably silicon is 0.22% ~ 0.34% further.
In this preferred alloy wrought steel, preferred described molybdenum is 0.38% ~ 0.49%.
In this preferred alloy wrought steel, the metallographic structure after described alloy wrought steel modifier treatment is sorbite tissue.
Alloy wrought steel of the present invention adopts conventional LF+VOD+VD (ladle oven process+vacuum-oxygen decarbonizing oven process+vacuum decarburization oven process) process for smelting steel to be prepared.
Role and preferred content range thereof can see the descriptions of relevant portion above in forged steel is smelted for each chemical composition contained by alloy wrought steel of the present invention.
Present invention also offers the preferred embodiment that some are concrete, each preferred embodiment, by sequence number arrangement, is followed successively by 1# ~ 12#.As shown in Table 3 below, the content that other element in preferred embodiment 1# ~ 12# is all less than or equal to other elements is less than or equal to 0.30% to their chemical composition; Comprise oxygen mass percentage content and be less than or equal to 0.0020%; Hydrogen mass percentage content is less than or equal to 0.0005%; Nitrogen mass percentage content is less than or equal to 0.0070%; Also comprise vanadium≤0.1%, titanium≤0.08%, tungsten≤0.04%, niobium≤0.05%.
The mechanical property of its correspondence as shown in Table 4 below.Alloy wrought steel of the present invention may be used for manufacturing brake disc of high-speed train.
Be described with the example that is fabricated to of Alloy Forging Steel Brake Disc of High-speed Train below.
The first step, first preparation meets the alloy wrought steel that in table 1, each chemical composition requires; Conventional LF+VOD+VD (ladle oven process+vacuum-oxygen decarbonizing oven process+vacuum decarburization oven process) is adopted to make steel refinery practice, smelt by the chemical composition proportioning of alloy wrought steel of the present invention as shown in table 1, the obtained alloy wrought steel steel ingot meeting each chemical composition requirement in table 1;
Second step, rerolls the alloy wrought steel steel ingot that the first step is obtained and makes round steel;
3rd step, forges for blank with the round steel that second step is obtained, obtains the forging blank of required alloy wrought steel, i.e. Alloy Forging Steel Brake Disc blank; Concrete forging flow process comprises: blank blanking → heating → ejection → heating → die forging → trimming, punching;
4th step, to the forging blank of the alloy wrought steel that the 3rd step obtains, namely Alloy Forging Steel Brake Disc blank is heat-treated; Described thermal treatment comprises first normalizing treatment, then carries out modifier treatment;
5th step, to the forging blank of the alloy wrought steel after thermal treatment, namely Alloy Forging Steel Brake Disc blank obtains retarding disc finished product after carrying out machining.
Table 3 chemical composition (%)
Sequence number |
C |
Si |
Mn |
P |
S |
Cr |
Ni |
Mo |
1# |
0.26 |
0.25 |
1.06 |
0.020 |
0.002 |
1.29 |
1.08 |
0.46 |
2# |
0.27 |
0.25 |
1.10 |
0.017 |
0.002 |
1.32 |
1.09 |
0.47 |
3# |
0.28 |
0.29 |
0.87 |
0.018 |
0.009 |
0.92 |
0.73 |
0.38 |
4# |
0.29 |
0.25 |
1.10 |
0.015 |
0.001 |
1.32 |
1.10 |
0.47 |
5# |
0.30 |
0.30 |
1.06 |
0.019 |
0.004 |
1.25 |
1.10 |
0.46 |
6# |
0.31 |
0.27 |
1.10 |
0.019 |
0.004 |
1.32 |
1.22 |
0.45 |
7# |
0.32 |
0.28 |
1.09 |
0.016 |
0.004 |
1.34 |
1.21 |
0.47 |
8# |
0.33 |
0.31 |
1.07 |
0.016 |
0.005 |
1.24 |
1.12 |
0.45 |
9# |
0.35 |
0.22 |
0.85 |
0.009 |
0.003 |
0.91 |
0.80 |
0.39 |
10# |
0.27 |
0.40 |
0.95 |
0.013 |
0.008 |
1.56 |
0.85 |
0.59 |
11# |
0.28 |
0.34 |
1.41 |
0.012 |
0.006 |
1.06 |
1.61 |
0.40 |
12# |
0.27 |
0.32 |
0.92 |
0.013 |
0.007 |
1.85 |
0.72 |
0.63 |
Table 4 mechanical property
Alloy wrought steel of the present invention for the manufacture of the forging of brake disc of high-speed train, thermal treatment and machining flow process is: alloy wrought steel steel ingot → alloy wrought steel round steel → blank blanking → heating → ejection → heating → die forging → trimming, punching → normalizing → modified → impeller blasting → flaw detection → machining → retarding disc finished product warehouse-in.
Below describe alloy wrought steel of the present invention heat treating method, the heat treating method of Alloy Forging Steel Brake Disc blank in other words.Concrete heat treatment process is:
First, first carry out normalizing treatment, after being namely warming up to 860 ~ 920 DEG C be incubated 3 ~ 5 hours, by blowing or similar fashion air-cooled to normal temperature.
Then, then carry out modifier treatment, insulation 3 ~ 5 hours after namely quenching is warming up to 860 ~ 920 DEG C, shrend, carry out temper subsequently, after being namely warming up to 550 ~ 620 DEG C be incubated 3 ~ 5 hours, by blowing similar fashion is air-cooled or by water spray or similar fashion water-cooled to normal temperature.
Preferably, the heat treating method of alloy wrought steel of the present invention or Alloy Forging Steel Brake Disc blank is: temperature-rise period when carrying out described normalizing treatment and quench treatment is, first be incubated 1 ~ 2 hour after being warming up to 650 DEG C ~ 700 DEG C, and then be warming up to 860 DEG C ~ 920 DEG C.The phase transformation when phase transformation of alloy wrought steel materials microstructure can be made so abundant, eliminate distortion and the crackle tendency of intensification heat-processed interalloy forged steel forging or Alloy Forging Steel Brake Disc blank further.
Preferably, the heat treating method of alloy wrought steel of the present invention or Alloy Forging Steel Brake Disc blank is: when carrying out described normalizing treatment and quench treatment, and heat-up rate is 120 DEG C ~ 200 DEG C/h.Control certain heat-up rate, can avoid because heat-up rate is too fast and cause thermal stresses large thus make alloy wrought steel of the present invention or Alloy Forging Steel Brake Disc blank produce the danger of distortion and crackle.
Alloy wrought steel of the present invention or alloy wrought steel mechanical property is after heat treatment: tensile strength is more than or equal to 1070MPa, yield strength is more than or equal to 905MPa, unit elongation is more than or equal to 14%, and relative reduction in area is more than or equal to 35%, and Brinell hardness number is 300 HBW ~ 388HBW.
In order to make heat treated effect more stable, when equipment for Heating Processing used has the function regulating heat-up rate, the heat-up rate of high temperature normalizing process and quench treatment is 120 DEG C ~ 200 DEG C/h; When equipment for Heating Processing used does not regulate the function of heat-up rate and heat-up rate is very fast, after high temperature normalizing and quenching are warming up to 650 DEG C ~ 700 DEG C, are incubated 1 ~ 2 hour, and then are warming up to 860 DEG C ~ 920 DEG C.
The thermal treatment process of alloy wrought steel of the present invention or alloy wrought steel for first to carry out normalizing treatment, then carries out modifier treatment (quenching+tempering).First carry out normalizing treatment, the banded structure in forging tissue and thick crystal grain can be eliminated, thinning microstructure; After carrying out modifier treatment (quenching+tempering) again, can obtain the uniform sorbite tissue of fine microstructures, material normal temperature strength increases substantially, and toughness also slightly improves.Fig. 3 and Fig. 4 is shown in the impact of normalizing treatment on alloy wrought steel mechanical property of the present invention, can see, there is the forging ratio of the alloy wrought steel of normalizing treatment and modifier treatment step simultaneously without normalizing treatment, only carry out the forging of the alloy wrought steel of modifier treatment, tensile strength and elongation two indexs have obvious advantage.
In the embodiment of alloy wrought steel of the present invention, within the scope of 850 DEG C ~ 1050 DEG C, carry out quenching heat treatment, Fig. 5 and Fig. 6 is shown in the impact of quenching temperature on the mechanical property of alloy wrought steel of the present invention.
From Fig. 5, Fig. 6, with the raising of quenching temperature, the intensity of alloy wrought steel of the present invention slightly improves, and plasticity is fallen after rising, quench within the scope of 860 ~ 920 DEG C, the mechanical property of alloy wrought steel of the present invention all can meet the mechanical property requirements of more than 250km/h EMU retarding disc alloy forged steel material, namely tensile strength is more than or equal to 1070MPa, yield strength is more than or equal to 905MPa, unit elongation is more than or equal to 14%, relative reduction in area is more than or equal to 35%, and Brinell hardness number is 300 ~ 388HBW.
The present invention's metallographic structure is after heat treatment sorbite tissue, and its concrete form amplifying 100 times is shown in Fig. 7, the concrete form of amplification 500 times is shown in Fig. 8.
The chemical composition that table 5 is depicted as a preferred embodiment of the present invention and prior art contrasts.
The chemical composition of table 5 embodiment of the present invention and prior art contrasts
Table 6 is depicted as embodiment of the present invention 1# and adopts the mechanical property after identical thermal treatment process process to contrast with prior art.The thermal treatment process that bi-material adopts is: be incubated 4 hours after being warming up to 900 DEG C, quenching is to normal temperature; And then carry out modifier treatment, insulation 4 hours after namely quenching is warming up to 900 DEG C, shrend, be incubated 4 hours after temper is warming up to 600 DEG C, blowing air is chilled to normal temperature.
The mechanical property of table 6 embodiment of the present invention and prior art contrasts
As can be seen from Table 6, the preferred embodiment of the present invention is by science, the rational proportion to various alloying element, and the mechanical property of obtained alloy wrought steel material is better than the mechanical property of prior art.Particularly, the tensile strength of the alloy wrought steel of the preferred embodiment of the present invention, yield strength, elongation and relative reduction in area are all apparently higher than prior art.
Table 7 is depicted as the thermal fatigue test result of the preferred embodiment of the present invention and prior art, namely retarding disc behaviour in service is imitated, sample is heated to 600 DEG C, insulation for some time, then the water of 20 DEG C is put into fast, after repeatedly carrying out 600 times, under metaloscope, observe the crack propagation situation of breach.Data in table 7 show: the cracking resistance of the preferred embodiment of the present invention obviously can be better than prior art.
The thermal fatigue test Comparative result of table 7 embodiment of the present invention 1# and prior art
Sample name |
V-notch place crack length (mm) |
Embodiment of the present invention 1# |
About 0.24 |
Prior art |
About 0.64 |
Alloy wrought steel composition of the present invention and performance meet the performance requriements of more than 250km/h EMU retarding disc completely, and have better toughness and tenacity.The present invention by the choose reasonable of the alloying constituents such as manganese, nickel, chromium and molybdenum in alloy forged steel and and the rational proportion of other chemical composition such as carbon, silicon, various chemical compositions in alloy wrought steel are obtained more reasonably mate, thus make alloy wrought steel material of the present invention after suitable thermal treatment, grain refining, obtain excellent comprehensive mechanical property, improve hardening capacity and thermostrength, normal temperature strength and hot strength have also been obtained and increase substantially.
The present invention is by suitably improving the content of nickel, and the content of Reasonable adjustment manganese, chromium, molybdenum element, both add intensity and turn avoid considerable influence to plasticity and toughness, thus the alloy wrought steel making the present invention obtain obtains excellent comprehensive mechanical property, overcome the prior art deficiency that plasticity and toughness obviously decline because intensity increases.
And the thermal treatment process of the forging of alloy wrought steel of the present invention or alloy wrought steel for first to carry out normalizing treatment, then carries out modifier treatment (quenching+tempering).First carry out normalizing treatment, the banded structure in forging tissue and thick crystal grain can be eliminated, thinning microstructure, then after carrying out modifier treatment (quenching+tempering), can obtain the uniform sorbite tissue of fine microstructures, tensile strength, the yield strength of material are further improved; Normal temperature strength and hot strength also have lifting by a relatively large margin; Forging distortion and crackle are inclined to less.
In addition, due to alloying element kind, reasonable quantity that the present invention adds, forging distortion and crackle are inclined to little, have excellent forging process performance, and a reasonable heat treatment process, are conducive to the application of this material in railway industry and Other Engineering field; Each chemical composition of the present invention is more easy to control simultaneously, and it is convenient to smelt, and easily, processing performance is good in forging, is more conducive to industrial production and controls and reduce manufacturing cost.
It is pointed out that the heat that the operating mode of retarding disc produces when braking is higher, require the heat-resisting of material, thermal diffusivity will be got well, and wear resistance is good simultaneously.For alloy wrought steel, usual hardness and intensity are directly proportional, and intensity is high, and hardness is also high, and the wear resistance of respective material might as well.Because the hardness ratio prior art of Alloy Cast Steel material of the present invention is higher, therefore, its wear resistance is also obviously better than prior art.
The smelting of alloy wrought steel of the present invention have employed LF+VOD+VD (ladle oven process+vacuum-oxygen decarbonizing oven process+vacuum decarburization oven process) and makes steel refinery practice, considerably reduce oxygen, hydrogen, oxide gas content and inclusion content, further increase the mechanical property of material.The steel-making refinery practice that other is similar can certainly be adopted.
Alloy wrought steel of the present invention can be used to forging railway parts, is especially suitable for the alloy steel forgings such as brake disc of high-speed train, also can be used for forging the parts that other have similar mechanical property requirements, as gear, snubber, hitch annex etc.