CN106893845A

CN106893845A - The process of thermal treatment and device of track

Info

Publication number: CN106893845A
Application number: CN201510945353.3A
Authority: CN
Inventors: 赵振荣
Original assignee: QINGDAO SANTONGDE METAL PRODUCTS Co Ltd
Current assignee: QINGDAO SANTONGDE METAL PRODUCTS Co Ltd
Priority date: 2015-12-17
Filing date: 2015-12-17
Publication date: 2017-06-27

Abstract

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

Description

The process of thermal treatment and device of track

Technical field

Technique on line the present invention relates to be used for the heat treatment of the track of rolling, the technique is used to improve rail The mechanical property of at least one superficial layer of road head, and it is related to the heat-treating apparatus for track, have It is related to the heat-treating apparatus on line for the track discharged from rolling system body.

Background technology

Include heat-treating apparatus and the different solution party of technique of the track for rolling in known technology Case, these devices and technique harden head more particularly to by hardening step.

Many in these devices is not arranged on one wire with rolling-mill housing (rolling stand). This means the heating follow-up with its is put with considerable in the grain bin of the track rolled before quenching heat treatment is carried out Energy ezpenditure and poor efficiency.

In other systems, alternatively, these devices are arranged along roll line：The track of rolling is discharged in solid Due in the roller tables (roller table) on ground；Then, track is taken out by operator, aforesaid operations device Including accurate lever system, and the manipulation of track is controlled during track undergoes heat treatment；And track is most Launched to cooling bed or plate by suitable ejection mechanism eventually.

Be heated or directly from milling train track by using to injecting cooling fluid on track head The injection nozzle of (water, air or the water mixed with air), or accommodated by the way that track head is immersed Undergo quick cooling in the tank of cooling fluid.

When using injection nozzle, due to the temperature unevenness in some parts of track and due to follow-up Different thermal expansions, it may appear that the defect that track is distorted in the longitudinal direction.

Although in any case, the temperature difference between the base portion of hot orbit and the head for having cooled down results in track Bending, but when alternatively use steeping tank when, realize in the longitudinal direction preferably cooling homogeneity； Have the disadvantage that the rigidity of used operator is not enough, and be insufficiently resistant to and suppress the bending.It is such Another of operator have the disadvantage, during processing, operator all the time in identical fulcrum and rail contact, Therefore track in itself on produce undesirable lightpenia domain.

The content of the invention

The main object of the present invention is the new technology being heat-treated on line of the track for obtaining rolling, the new work Skill ensures to obtain homogeneous fine pearlite knot in the whole predetermined surface thickness of track head Structure, due to improved toughness, the track is particularly suitable for the use in perishing environment.

Another object of the present invention is to obtain the heat-treating apparatus for track, and described device is with rolling Unite placement into a line, it is simple in present apparatus structure compared with existing device, with robustness high, And need less maintenance.It is contemplated that by providing for the online of the track from rolling system discharge Upper process of thermal treatment realizes purpose disclosed above, and the technique comprises the following steps：

Aerial first cooling step of track, until the surface temperature of track head reaches at least 720 ℃；By the second cooling step of cooling fluid, until the surface temperature of track head is reached than Ar3 temperature It is high 50 DEG C to 150 DEG C, to avoid the phase transformation from austenite to pearlite；

Aerial the 3rd cooling step with the predetermined duration, by the 3rd cooling step, Surface temperature balance is until the temperature of the superficial layer of track head, the superficial layer is with apart from surface The depth of the scope between 15mm to 25mm；

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

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

Another aspect of the present invention provides the dress being heat-treated on line for the track discharged from rolling system Put, described device includes at least one moveable chassis, the moveable chassis then includes：

The roller tables of longitudinal direction, the roller tables includes roller pair, and roller is to being suitable for being received from system row along rolling axle The track for going out, keeps the rolling position of track, and the roller tables is suitable for around the longitudinal axis parallel to rolling axle Rotation, so that track head is downward；And the tank of longitudinal direction, longitudinal tank is for accommodating cooling stream Body, track head can be soaked in cooling fluid.

Advantageously, the inventive system comprises at least one roller tables, the roller tables is allowed preferably along roll line Guide rail, so as to keep the position identical position discharged from last rolling-mill housing with track, i.e. track Symmetry axis be maintained at substantially horizontal position.Identical roller tables also provide firm support to track, Manipulation during heating treatment to track and by track unloading on the cooling plate.Therefore, it is of the invention The roller tables of device performs all these functions in the mode different from traditional roller tables, and traditional roller tables, replace Dai Di, is only used for the track of transhipment rolling, and therefore need to be combined with special operator device.

The further advantage of device of the invention shows as described device and provides two roller tables with wheel, Roller tables alternately and with axial direction is aligned with roll line, it is allowed to two heat treatments almost simultaneously of track, Improve the output of the system.By this way, compared with the output realized using known device, Realize the output of twice, and the rolling speed with the scope between 8m/s to 10m/s.

Advantageously, the whole length of track is immersed in tank ensures the uniformity for the treatment of, due to the present apparatus Rigidity, the thermal deformation of track is substantially avoided or is reduced to minimum, and is also ensured to last The greater flexibility of the manipulation of cooling step, last cooling step is for obtaining final desired structure It is most important.The result of fine pearlitic grain depends on the cooldown rate in the final step and takes Certainly in the deformation of the material obtained in rolling-mill housing.It is therefore preferable that high cooldown rate, high cooldown rate exists The formation of undesirable bainite and/or bainite-sorbite structure is not caused in any case.

Process according to the invention advantageously provides four cooling steps, and two of which passes through air and two By the water with additive or by other suitable cooling liquids.The rail obtained by this technique The head in road shows following property：High rigidity (340-420HB)；High-wearing feature；Enough toughness；It is high resistance to tired Lao Xing；Mechanical property mentioned above is kept under low-down operation temperature (until -600 DEG C)；At least The homogeneous fine pearlite structure of the depth of 15-25mm；At the end for the treatment of, the good surface of track Quality and good glacing flatness；In the absence of crizzle.

Specific embodiment

The process of thermal treatment on line of the track for being discharged from rolling system is disclosed above to realize Purpose, the technique comprises the following steps：

Claims

1. one kind process of thermal treatment on line, the technique is used for from the heat on line of the track of rolling system discharge Reason, the technique is comprised the following steps：Aerial first cooling step of track, until track head Surface temperature reach at least 720 DEG C；The soaked in the tank for accommodating cooling fluid by the track head Two cooling steps, until the surface temperature of track head reach it is higher than Ar3 temperature 50 DEG C to 150 DEG C, to avoid From austenite to the phase transformation of pearlite；Aerial the 3rd cooling step with the predetermined duration Suddenly, by the 3rd cooling step, superficial layer is tempered the temperature until 720-840 DEG C by the heat of internal layer, And the surface temperature balance is until the temperature of the superficial layer of track head, the superficial layer is with distance The depth of the scope between the 15mm to 25mm of surface；The cooling fluid is being accommodated by the track head The 4th cooling step soaked in tank, until the surface temperature of track head is reached less than 500 DEG C, by described 4th cooling step, occurs from austenite to the phase transformation of pearlite；Wherein, it is cold in the 4th cooling step But speed is equal to 2-7 DEG C/s；And wherein, the pearlite has with fine in the superficial layer The homogeneous structure of granularity, homogeneous mechanical property is obtained hence along the superficial layer.

2. technique according to claim 1, it is characterised in that the 3rd cooling step is by by orbital head Portion takes out from the tank to be carried out.

3. a kind of for heat-treating apparatus on line, described device is used to exist from the track of rolling system discharge It is heat-treated on line, described device is adapted for carrying out the technique described in claim 1, described device is included at least One moveable chassis, the moveable chassis includes：The roller tables of longitudinal direction, it abuts the rolling system The outlet of system is placed and including roller pair, the roller to the profile for being endowed shape with waist-bottom junctional area Domain receives, guides and clamps the track from rolling system discharge along rolling axle consistently, keeps the rail The rolling position in road, the roller tables is configured to around the longitudinal axis rotation parallel to rolling axle, so that orbital head Portion is downward；And the tank of longitudinal direction, it is used to accommodate cooling fluid, and track head can be immersed in cooling stream In body, longitudinal tank has the longitudinal extent of the longitudinal extent at least equal to track, and It is arranged on the base portion of the chassis.