1、火工矫正程序Procedure for Distortion Correction by Flame客户项目号 Client No.所有项目 All Projects编 制 Edit审 查 Audit批 准 Authorization公司订单 Order No.通用火工矫正程序 General Procedure for Distortion Correction by Flame文献编号 Document No.S02 THM 2023 001 A0版本 VersionA0页码 Pages1/252023-11-27/使用部门 Department生产部办公室/加工科/组立一科/组立二科/组
2、立三科/品质保证部Fabrication Office/Processing Section/1st Assembly Section/2nd Assembly Section/3rd Assembly Section/QA Dept版本号Version修订内容Modifications修订Edit审核Audit批准Authorization日期Date1 火工矫正的目的 Purposes火工校正重要是用来消除钢板扎制、热切割、焊接产生的残余应力和变形。在焊接钢结构制造中最重要是用来对焊接变形的校正。Distortion correction by flame is mainly used f
3、or eliminating the resident strength and distortion from plates rolling, heat cutting and welding. In welding steel structures this process mainly applies for the correction of welding distortion.2 火工校正的原理 Principle火焰矫正是运用金属热胀冷缩的物理特性,采用火焰局部加热金属,热膨胀部分受周边冷金属的制约,不能自由变形,而产生压塑性变形,冷却后压塑性变形残留下来,引起局部收缩,即在被加
4、热处产生积聚力,使金属构件变形获得矫正。Flame correction is based on the characteristic of steel expanding with heat and contracting with cold. After partial heating of the steel, the pressing distortion coming from pressure of heated parts will contract when cooling down, creating strength in pre-heated place, so as t
5、o correct the distorted metals. 3 焊接变形的种类 Distortion Groups3.1 纵向收缩变形 Longitudinal Contract Distortion构件焊后在焊缝方向产生收缩。焊接结构焊后出现的收缩变形是难以修复的,必须在构件下料时加放余量。The metal contracts in the direction of welding seam and this contracting distortion is hard to correct. During material preparation, this must be seri
6、ously considered and leave enough allowance.3.2 横向收缩变形 Horizontal Contract Distortion构件焊后在焊缝横向产生收缩。焊接结构焊后出现的收缩变形是难以修复的,必须在构件下料时加放余量。The metal contracts in the direction of horizontal welding seam and this contracting distortion is hard to correct. During material preparation, this must be seriously
7、considered and leave enough allowance.3.3 角变形 Angle Distortion 构件焊后,构件的平面围绕焊缝发生的角位移。重要是由于焊缝截面形状不对称,或施焊层次不合理致使焊缝在厚度方向上横向收缩量不一致引起的。The angle move around the weld seam after welding and this mainly occurs because of asymmetric of welding sections or inappropriate welding layers, which lead to the diffe
8、rent contracting in the direction of weld thickness.3.4 波浪变形 Wave Distortion 薄板焊后易产生这种失稳变形,形状呈波浪状。产生因素是由于焊缝的纵向和横向收缩在拘束度较小结构部位导致较大的压应力而引起的变形,或由几个互相平行的角焊缝横向收缩产生的角变形而引起的组合变形,或由上述两种因素共同作用而产生的变形。Thin plates will occur wave distortion after welding because of the strength from contracts in the longitudina
9、l and horizontal direction of welding seam, or from the combined angle distortion caused by the horizontal contracts of several paralleled fillet welds, or both above. 3.5 弯曲变形 Bending Distortion 构件焊后发生弯曲。弯曲变形是由纵向收缩引起和或横向收缩引起。Bending distortion happens after welding because of longitudinal and horiz
10、ontal contracts. 3.6 扭曲变形 Warping Distortion 焊后沿构件的长度出现螺旋形变形,这种变形是由于装配不良,施焊顺序不合理,致使焊缝纵向和横向收缩没有一定规律而引起的变形。Spiral Distortion from the length of welded parts mainly occurs because of bad fitting and inappropriate welding procedures which cause mess in longitudinal and horizontal contraction in weld sea
11、ms.4 火焰加热对材料性能的影响 Influence of Heating to Material w(C)小于0.25%的低碳钢,在通常火焰加热、冷却(涉及水冷)时,不易获得马氏体组织,仍保持钢材本来组织,即铁素体加珠光体,因此这种钢火焰矫正加热、冷却对力学性能影响不大。The low carbon steel that W(c) under 0.25% will not easily get marten site structure and keeps its original structure during normal heating and cooling (including
12、 water cooling), thus this kind of flame correction and cooling has very limited impact to its mechanical properties. 低合金钢采用火焰局部加热空冷对力学性能无显著影响、且疲劳实验对刚度也没有影响。但如冷却速度过快也能出现低碳马氏体组织,影响力学性能。所以火焰矫正应控制加热温度和冷却速度。如若采用浇水冷却,最佳加热温度不超过7230C。Partial flame heating and air cooling has no serious impact to mechanical
13、 properties to low carbon alloy steel. Meanwhile the fatigue test also has no impact to stiffness. Quick cooling can cause low carbon marten site structure and impact its mechanical properties so the heating and cooling speed needs to be controlled. The heating temperature should not exceed 7230C wh
14、en using water cooling. 5 火焰矫正基本参数选择 Basic Reference for Distortion Correction5.1 火焰加热温度 Heating Temperature火焰矫正根据材质、板厚和加热方法等不同情况,选择不同的加热温度。可分为低温加热、中温加热和高温加热三种温度。Heating temperature differs according to different materials, plates thickness and heating methods, usually divided into low temperature h
15、eating, middle temperature heating and high temperature heating.5.1.1 低温加热 Low Temperature Heating低温加热温度为5006000C。低温加热应用于板厚小于6mm的薄板,由于低温加热最高温度在相变之下,适宜含碳量(质量分数)大于0.25%的碳素钢和合金高强度钢火焰矫正。低温加热允许浇水(清水)冷却,如600MPa级合金高强度钢可在4500C浇水冷却。Temperature ranges from 5006000C. This applies to thickness less than 6mm. As
16、 the heating temperature is blow the phase changing, this heating is mainly used for the distortion correction of carbon steel and high strength alloy steel whose w(c) is lower than 0.25%. This heating can use water (fresh water) cooling, e.g. cool the 600MPa high strength alloy steel at 4500C.5.1.2
17、 中温加热 Middle Temperature Heating温度为6007000C。在这个温度范围,火焰矫正最佳。同时也允许较大的冷却速度,如浇水冷却。中温加热适宜板厚612mm的钢板件火焰矫正。但对含碳量(质量分数)大于0.35%的碳素钢和低合金高强度钢加热温度要控制准确,不得超过7230C。Heating temperature ranges from 6007000C and this range is the best temperature for flame correction, also allowing high speed cooling like water cool
18、ing. The thickness of plates is 612mm. For the carbon steel and low alloy high strength steel whose w(c) is greater than 0.35%, the heating temperature needs to be controlled and not to exceed 7230C. 5.1.3 高温加热 High Temperature Heating加热温度为7238500C 。高温加热合用于大厚板加热,对于厚板加热效果比低温加热和中温加热效果要好。板厚在1416mm加热温度在
19、7508000C,大于20mm板加热温度在8500C。对于含碳量(质量分数)大于0.35%的碳素钢和合金高强度钢不能采用高温加热矫正。Temperature ranges from 7238500C and this mainly applies to thick plates. The heating temperature for plates thickness around 1416mm is 7508000C and 8500C for thickness above 20mm. Carbon steel and alloy steel whose w(c) is great tha
20、n 0.35% can not use high temperature heating.火焰加热温度不允许超过8500C(过火),这样力学性能会变坏,冲击性能减少,同时由于加热温度过高,使金属接近熔化变软,由于气体喷射会把金属表面吹成凹坑或波纹,使钢件受到损伤。此外加热温度过高,使金属表面晶界处被氧气侵入而生成氧化物形成空洞或裂纹,金属表面会生成较厚的氧化皮。The flame temperature should not exceed 8500C (overheated), otherwise the process will damage its mechanical propertie
21、s and lower its impact performance. Overheating will also melt the steel and causes pits or waves. Moreover overheating will make the crystallized surface into oxide and cause cavity or cracks in the metal surface.5.1.4 火焰加热温度的控制 Temperature Control对于含碳量(质量分数)小于0.25%的碳素钢和低合金钢,由于加热温度较宽,可以近似的凭钢材的加热颜色估
22、计加热温度。从钢材表面颜色判断温度有一定误差,并且与观测者的经验和现场的光线亮度关系很大。因此对于含碳量(质量分数)大于0.35%的碳素钢和合金高强度钢应采用测温笔或测温仪器测定比较可靠。For carbon steel and low alloy steel whose w(c) is lower than 0.25%, as the heating temperature range is wide, the heating temperature can be judged from the heating colors. But this method is not accurate
23、and differs according to the watchers experience and working conditions. For carbon steel and alloy steel whose w(c) is great than 0.35%, temperature measurement should use temperature measuring pen or equipments.颜色 Color温度/Temperature颜色 Color温度/ Temperature深褐红色 Dark Maroon550580亮红色 Light Red830900褐
24、红色 Maroon580650橘黄色 Orange9001050暗红色 Dark Red650730暗黄色 Dark Yellow10501150暗樱红色 Dark Cherry-red730770亮黄色 Light Yellow11501250樱红色 Cherry-Red770800白黄色 White Yellow12501300深樱红色 Deep Cherry-red800830-5.2 加热火焰氧与乙炔燃烧比 Flame Oxide and Acetylene 由于氧气和乙炔混合比例不同,燃烧的火焰可以分为中性焰、氧化焰和碳化焰三种。火焰都由焰心、内焰、外焰组成。As the ratio
25、 of Oxide and acetylene differs, the flame can be divided into neutral flame, oxidant flame and phosphate flame. The flame is consisted of flame heart, inner flame and outer flame.5.2.1 中性焰 Neutral Flame中性焰燃烧后的气体中即无过剩的氧气,也无过剩的乙炔。The flamed air of neutral flame has no oxide or acetylene.焰心紧靠烤嘴是一个光亮的白
26、色圆柱体,其限度随混合气体的喷射速度增大而增长,温度不是很高。在焰心尖端距离工件表面24mm,此区火焰温度最高,并在还原性气氛保护下,可避免氧化。Flame heart is one light column and grows with the spraying speed of mixed gas. Its temperature is not high and distance from the peak of flame heart to the surface of workpiece is 24mm. In this area the flame temperature is th
27、e highest and protected under reducing gas from oxidization.内焰在焰心之外,颜色较暗。Inner flame is out of the flame heart and its color is comparative dark.外焰在内焰之外与周边空气接触,呈淡蓝色,具有氧化性,温度也低。Outer flame is out of the inner flame and directly contacts the air with light blue color. The outer flame is oxidant and lo
28、w temperature.适合矫正1030mm厚度的钢板 Outer flame applies to correction of 1030mm thickness plates.5.2.2 碳化焰 Carbon Flame火焰燃烧后气体中尚有部分乙炔未成燃烧,焰心呈蓝白色,内焰呈淡白色,外焰带橘红色。The gas after flame burning has partial acetylene left and its flame heart is blue-white, while the inner flame is light white and the outer flame
29、is orange red. 碳化焰由于乙炔过剩,燃烧速度减慢,因此整个火焰比中性焰长,且较柔软,温度也较低。As the left acetylene exists, the carbon flames burning speed is low and its flame length is greater than neutral flame, with soft light and lower temperature. 对于大于30mm以上钢板,可采用碳化焰缓慢加热,以便逐渐烤透钢板,避免钢板表面温度较高,而内部温度较低的现象。For thickness above 30mm, use
30、carbon flame to heat slowly to increase the whole plates temperature, so that the outer and inner of plate have no great temperature difference.5.2.3 氧化焰 Oxidized Flame由于火焰中氧量的增长,氧化反映剧烈,使火焰各部分长度均变小,焰心短而尖,内外焰层次不清,火焰呈紫蓝色。火焰挺直,并发出“嘶嘶“声。As the oxide increases, the oxidation reaction is great and the fla
31、me length is shorter with no evident flame layer. The flame is violet blue and straight.火焰矫正特点:加热快、生产效率高,通过钢材沿厚度方向温度不均匀分布而产生不均匀收缩来达成矫正变形的目的时,可采用氧化焰较快的加热钢板表面。一般用于厚度10mm以下钢板。Flame Characteristic: high speed heating. When heat the plate in the direction of thickness, the unequal temperature allocates w
32、ill cause unequal contraction.5.2.4 如采用氧与丙烷,火焰形状与乙炔气稍有不同,内焰呈伞状,呈明亮青白光状,火势旺盛为宜。如呈模糊的兰色则是丙烷过少或氧气过多,呈白色时氧气过少。加热时将内焰伞状接触钢板。The mix of oxide and propane has different flame shape. Its inner flame has umbrella shape and its light is bluish white. If the color is blurry blue, the propane is too much or the
33、 oxide is less. When the color is white, the oxide is less. Use the inner flame to contact the plate.5.3 火焰矫正的加热速度和冷却速度 Heating and Cooling Speed5.3.1 火焰矫正加热速度 Heating Speed在加热温度和烤嘴一定期,火焰矫正的加热速度随板厚增长而减小。但对火焰矫正焊接角变形,如线状加热时速度慢,沿厚度方向温差小,矫正效果不佳。如速度低于250mm/min以下时,高温加热会使表面过热,出现缺陷。The heating speed will lo
34、wer with the increase of plate thickness when the heating temperature and spraying gun is set. But in correction of welded angle, if the heating speed is slow, the temperature difference in the direction of thickness is small and the correction effect is not good. If the speed is below 250mm/min, hi
35、gh temperature heating will cause overheating to surface and lead to defects. 板厚T(mm)加热速度(mm/s)气体种类gas 246810121416182225氧-丙烷 Oxide-Propane13201113611795745.3.2 冷却速度 Cooling Speed火焰矫正的冷却速度分为两种,一种是空气中冷却(空冷),另一种是喷水冷却。The cooling of flame correction is divided into air cooling and water cooling.空冷速度相称于
36、水冷速度的2%3%,冷却速度较慢,可以获得类似于正火的金相组织。含碳量(质量分数)大于0.25%的钢或合金钢,假如加热温度超过7230C以上,必须空冷。空冷缺陷是:冷却时间长,生产效率低。The air cooling speed is around 2%3% of water cooling and can get the microstructure like normalized structure. For steel or alloy steel whose w(c) is great than 0.25%, if the heating temperature exceeds 72
37、30C, air cooling is applied. Shortness of air cooling is the low speed and efficiency.喷水冷却使用清水作为冷却介质。因盐水或其他溶液冷却速度过快易形成裂纹等问题,所以不允许使用。Water cooling shall use fresh water as the cooling medium. Salty water and other solvents will cause cracks, this kind of medium is not allowed.水冷应用于低温矫正和中温矫正,对于含碳量(质量分
38、数)小于0.25%的碳素钢高温矫正也可采用喷水冷却。喷水冷却效率可以提高三倍以上。但对于w(C)0.25%的碳素钢和低合金高碳钢,中温加热和高温加热时不允许采用喷水冷却。Water cooling applies to low temperature and middle temperature correction. For carbon steel whose w(c) is lower than 0.25%,water cooling can also apply. The water cooling efficiency is 3 times of air cooling. But f
39、or w(c) above 0.25%, water cooling is not allowed in middle temperature and high temperature cooling.5.3.3 水火距(喷水的水嘴与火焰加热烤嘴之间的距离)Distance between water spray and flame spray水火距离过大或过小都会减小成型效果。水火距决定了火焰成型的温度场和拘束刚度,水火距太近,热量被水带走太多,温度场过低,矫正成型效果减小,正面水冷还会减小正反两面温度差,显著减少角收缩。水火距过大,则拘束刚度下降,加热过程中压缩作用减小也使成型效果减小。正
40、面水冷水火距为90mm为宜,背面水冷水火距以120mm为宜。This distance will affect the formalization because it determines the temperature of flame and constrict stiffness. Small distance will cause heating dissipating, creating low temperature and little formalizing effect. Over distance will also lower the formalizing effec
41、t. Usually the distance between positive water and flame spray is 90mm while the opposite is 120mm.5.3.4 水流量的选择 Water Flow Selection水流量的大小起两个方面作用:一是决定了冷却作用的强弱,二是决定了浸水前沿距火焰中心的距离(实际水火距),因此水流量和水火距共同拟定了火焰成型的冷却条件,是火焰成型的重要参数之一。合适的水流量在53100ml/s为宜。The water flow determines the cooling effect and the actual
42、distance between water and flame. The appropriate water flow is 53100ml/s.5.3.5 火焰能率和烤嘴角度 Flame Efficiency and Gun Angle火焰能率重要依据每小时可燃气体的消耗量(L/h)来拟定,而气体消耗量又取决于烤嘴大小,所以一般烤嘴大小表达火焰能率大小。只有适当的火焰能率,才干给予足够的能量烤透构件,达成火焰矫正目的。Flame efficiency can be calculated with consumable gas (L/h). As consume of gas is dete
43、rmined by the mouth size of spraying gun, we use the mouth size to substitute flame efficiency. Only proper flame efficiency can lead to proper correction.烤嘴与构件的夹角称为烤嘴角度,烤嘴的倾斜角度大小与火焰的运用率有直接关系,烤嘴与加热构件成90度角即垂直,火焰运用率最高,通常火焰矫正烤嘴的角度为8090度,如需减少加热温度可以将角度减小。The angle between spraying mouth and structure is
44、the gun angle, which has direct relationship with usage of flame. 90 degree of gun angle is the best usage of flame. Usually the angle is 8090 degree. Reduce the angle to lower the heating temperature.6 火焰矫正的加热方法 Heating Method6.1 圆点加热法 Circle Point Heating圆点加热法是火焰在构件上加热为圆点形面积的一种火焰矫正方法。This method i
45、s to heat the structure with an area of circle point.6.1.1 在板上加热一个圆点形面积,沿板厚温度分布可构成圆柱或圆锥加热体,当加热温度至2023C以上,冷却后会沿加热体圆柱径向产生残余的压塑性变形和应力,则加热体径向收缩,其收缩力称为集结力。Heat on an circle area to form the column or cone. When heated above 2023C, the resident strength from heated column will contract.6.1.2 圆点加热面积大小根据板厚决
46、定:The circle points area is determined by the thickness of the plate板厚 Th.123456810121416182022加热点直径Diameter5101520253035404850556062646.1.3 应用 Application圆点加热法重要用于构件板面波浪变形(不平度)的矫平和构件弯曲变形的矫直。This method mainly applies to the correction of wave distortion and bending distortion.6.2 线状加热法 Line Heating
47、 Method线状加热是火焰在构件上沿直线、曲线或环形的连续加热方法,被加热的构件上的加热面积呈现一条较窄的带状。Line heating is the heat method of the structure upon line, curve or circle and after heating there will be one strap on heated area.6.2.1 线状加热的特点 Characteristic火焰在构件上加热一线状同在构件上堆焊一条焊缝的焊接变形同样,有沿加热长度方向的纵向收缩变形和垂直于加热长度方向上的横向收缩变形以及以加热线为轴的角变形。Line h
48、eating will create longitudinal contract and horizontal contract as well as line axle deformation.6.2.2 线状加热操作方法 Processing Method线状加热可以分为直线加热、环形加热(螺旋形)和曲线加热(波浪形)三种基本形式。Line heating is divided into straight line heating, circle (spiral) heating and wave heating.线状加热其加热线越宽,在温度相同的情况下,产生的横向线性热膨胀越大,则火焰矫正产生的压塑性变形越大,火焰矫正效果越好。但易引起板件局部翘曲变形。所以线状加热宽度,应根据构件的变