CN108148981A

CN108148981A - The process of thermal treatment and device of track

Info

Publication number: CN108148981A
Application number: CN201611105076.6A
Authority: CN
Inventors: 曲立辉
Original assignee: Qingdao Xiaomi Star Electronic Technology Co Ltd
Current assignee: Qingdao Xiaomi Star Electronic Technology Co Ltd
Priority date: 2016-12-05
Filing date: 2016-12-05
Publication date: 2018-06-12

Abstract

For the process of thermal treatment on line of the track of rolling, the technique ensures to obtain uniform fine pearlitic texture in the entire predetermined surface thickness of track head.The new equipment of heat treatment for the track with rolling system on one wire is also disclosed, and compared with known device, which has simpler structure, has high robustness, and need less maintenance.

Description

The process of thermal treatment and device of track

Technical field

The present invention relates to the technique on line of the heat treatment of the track for rolling, the technique is used to improve track head At least one superficial layer mechanical property, and be related to the heat-treating apparatus for track, more particularly to for from rolling The heat-treating apparatus on line of the track of system discharge processed.

Background technology

Include in known technology for the heat-treating apparatus of track of rolling and the different solutions of technique, this A little devices and technique harden head more particularly to by hardening step.

Many in these devices does not arrange on one wire with rolling-mill housing (rolling stand).This meaning It puts with its subsequent heating with considerable energy expenditure and inefficient in the grain bin for the track rolled before quenching heat treatment is carried out Rate.

In other systems, alternatively, these devices are arranged along roll line：The track of rolling, which is discharged in, is fixed on ground Roller tables (roller table) on；Then, track is taken out by operator, and aforesaid operations device includes accurate lever system, and The manipulation of track is controlled during track is subjected to heat treatment；And track is launched eventually by suitable ejection mechanism to cold But on bed or plate.

Heated or directly from milling train track by using on track head inject cooling fluid (water, air The water that is either mixed with air) injection nozzle or be subjected to by immersing track head in the tank for accommodating cooling fluid It is quickly cooled down.

When using injection nozzle, due to the temperature unevenness in certain parts of track and due to subsequent difference Thermal expansion, it may appear that the defects of track distorts in the longitudinal direction.

Although in any case, the temperature difference between the base portion of hot orbit and the head cooled down results in the curved of track Song, but when alternatively using steeping tank, realize in the longitudinal direction preferably cooling homogeneity；Shortcoming is used The rigidity of operator is insufficient, and is insufficiently resistant to and inhibits the bending.Such operator another disadvantage is that, locating During reason, operator always in identical fulcrum and rail contact, therefore track in itself on generate undesirable lightpenia domain.

Invention content

The main object of the present invention is the new process being heat-treated on line for the track for obtaining rolling, and the new process ensures Uniform fine pearlitic texture is obtained in the entire predetermined surface thickness of track head, due to improved tough Property, which is particularly suitable for the use in perishing environment.

Another object of the present invention is the heat-treating apparatus obtained for track, and described device and rolling system are into one Bar line is placed, simple in present apparatus structure compared with existing device, has high robustness, and need less maintenance. The present invention is directed to institute more than being realized by providing from the process of thermal treatment on line for the track that rolling system is discharged is public The purpose opened, the technique include the following steps：

Aerial first cooling step of track, until the surface temperature of track head reaches at least 720 DEG C；Pass through Second cooling step of cooling fluid, until the surface temperature of track head reaches 50 DEG C to 150 DEG C higher than Ar3 temperature, to keep away Exempt from the phase transformation from austenite to pearlite；

The aerial third cooling step with the predetermined duration, by third cooling step, surface Equalized temperature is until the temperature of the superficial layer of track head, the superficial layer have apart from surface 15mm to the model between 25mm The depth enclosed；

By the 4th cooling step of cooling fluid, until the surface temperature of track head reaches less than 500 DEG C, by Four cooling steps occur from austenite to the phase transformation of pearlite；

Wherein described pearlite has the uniform structure with fine granularity in the superficial layer.

Another aspect of the present invention is provided for the heat-treating apparatus on line for the track discharged from rolling system, institute It states device and includes at least one moveable trolley, the moveable trolley then includes：

The roller tables of longitudinal direction, the roller tables include roller pair, and roller is to being suitable for receiving the rail discharged from the system along rolling axis Road, keeps the rolling position of track, and the roller tables is suitable for around the longitudinal axis rotation for being parallel to rolling axis, so that track head Downward；And the tank of longitudinal direction, for longitudinal tank for accommodating cooling fluid, track head can be soaked in cooling fluid In.

Advantageously, the inventive system comprises at least one roller tables, the roller tables allows preferably along roll line guide rail Road, so as to keep with track from the identical position in the position that last rolling-mill housing is discharged, i.e. the symmetry axis of track is maintained at base Horizontal position in sheet.Identical roller tables also provide firm support to track, during heating treatment to the manipulation of track with And by track unloading on the cooling plate.Therefore, the roller tables of the apparatus according to the invention is held in a manner of different from traditional roller tables The all these functions of row, and traditional roller tables, alternatively, are only used for the track of transhipment rolling, and therefore need with it is dedicated Operator device is combined.

The further advantage of the device of the invention shows as described device and provides two roller tables with wheel, and roller tables is handed over It alternately and with axial direction is aligned with roll line, allows the heat treatment almost simultaneously to two tracks, improve the system Output.In this way, compared with using the output that known device is realized, twice of output is realized, and have In the rolling rate of 8m/s to the range between 10m/s.

Advantageously, the whole length of track is immersed in ensures the uniformity of processing in tank, due to the rigidity of the present apparatus, rail The thermal deformation in road is substantially avoided or is reduced to minimum, and also ensures the manipulation to last cooling step more Big flexibility, last cooling step are most important for obtaining final desired structure.Fine pearlitic grain Result depend on the final step in cooldown rate and the material depending on being obtained in rolling-mill housing deformation.Cause This, preferably high cooldown rate, high cooldown rate lead to undesirable bainite and/or bainite-rope in no instance The formation of family name's body structure.

Process according to the invention advantageously provides four cooling steps, and two of which passes through tool by air and two There is the water of additive or by other suitable cooling liquid.The head of the track obtained by this technique shows following Property：High rigidity (340-420HB)；High-wearing feature；Enough toughness；High fatigue durability；It is (straight in low-down operation temperature To -600 DEG C) under keep mechanical property described above；At least uniform fine pearlite structure of the depth of 15-25mm； At the end of processing, the good surface quality and good glacing flatness of track；There is no crizzles.

Specific embodiment

Purpose disclosed above, institute are realized for the process of thermal treatment on line for the track discharged from rolling system Technique is stated to include the following steps：

Claims

1. a kind of process of thermal treatment on line, the technique are used for the heat treatment on line of track discharged from rolling system, institute Technique is stated to include the following steps：Aerial first cooling step of track, until the surface temperature of track head reach to It is 720 DEG C few；The second cooling step impregnated in the tank for accommodating cooling fluid by the track head, until track head Surface temperature reaches 50 DEG C to 150 DEG C higher than Ar3 temperature, to avoid the phase transformation from austenite to pearlite；Aerial tool There is the third cooling step of predetermined duration, by the third cooling step, superficial layer is tempered by the heat of internal layer Until 720-840 DEG C of temperature, and surface temperature balance is until the temperature of the superficial layer of track head, the superficial layer With in the depth apart from surface 15mm to the range between 25mm；The cooling fluid is being accommodated by the track head The 4th cooling step impregnated in tank until the surface temperature of track head reaches less than 500 DEG C, is walked by the described 4th cooling Suddenly, occur from austenite to the phase transformation of pearlite；Wherein, the cooldown rate in the 4th cooling step is equal to 2-7 DEG C/s；And And wherein, the pearlite has the uniform structure with fine granularity in the superficial layer, therefore along the table Face layer obtains uniform mechanical property.

2. technique according to claim 1, which is characterized in that the third cooling step by by track head from described Progress is taken out in tank.

3. one kind, for heat-treating apparatus on line, described device is used at the heat on line for the track that rolling system is discharged Reason, described device are adapted for carrying out technique described in claim 1, and described device includes at least one moveable trolley, institute Moveable trolley is stated to include：The roller tables of longitudinal direction is placed against the outlet of the rolling system and including roller pair, the roller pair It with consistent with waist-bottom juncture area received with the profile for being endowed shape along rolling axis, guide and clamp from described and roll The track of system discharge processed, keeps the rolling position of the track, and the roller tables is configured to around the longitudinal direction for being parallel to rolling axis Axis rotates, so that track head is downward；And the tank of longitudinal direction, it is used to accommodate cooling fluid, track head can be immersed in In cooling fluid, longitudinal tank has the longitudinal extent of the longitudinal extent at least equal to track, and is set It puts on the base portion of the trolley.