Overview of casting defects 铸件缺陷en-ch课件

1、Slide No. 1 J.Vierimaa Overview of casting defects 铸件缺陷的概述铸件缺陷的概述 / J.VierimaaSlide No. 2 J.VierimaaOverview of casting defects 铸件缺陷的概述铸件缺陷的概述The general origins of casting defects导致铸件缺陷的几大根源- casting design铸件的设计铸件的设计- technique of manufacture = method -生产技术生产技术=方法方法- application of the technique =

2、workmanship -技术的实施技术的实施=作业过程作业过程Process steps 工序步骤- Defect recognition 识别缺陷- Defect occurrences 发生缺陷- Defect removal 解决缺陷Slide No. 3 J.VierimaaExample of casting design-设计导致产品缺陷举例设计导致产品缺陷举例Plenty of separate bosses which need feeding.单独的套筒过多，需要很多冒口Slide No. 4 J.VierimaaExample of method-因方法导致产品缺陷举例因

3、方法导致产品缺陷举例Put machined surfaces to drag mould ( = face down ) 将加工面放在下模（=加工面朝下）Slide No. 5 J.VierimaaExample of method-因方法导致产品缺陷举例因方法导致产品缺陷举例Proper lay-out done before machining / OK.在加工之前需要画好线/OKBack supports in use to reduce bending due the fixing / OK放置后支撑，防止固定时变形/OKCeramic inserts in use in machi

4、ning / OK加工时使用的陶瓷插件/OKSlide No. 6 J.VierimaaExample of workmanship因作业过程导致产品缺陷举例因作业过程导致产品缺陷举例Limestone used from broken bags; CaO Ca ( OH )2使用破包装袋里面取出的石灰石氧化钙发生反应生成了氢氧化钙Mould has leaked during pouring due missing clamp.由于夹子不够，浇注的时候砂型漏钢水Slide No. 7 J.VierimaaExample of workmanship因作业过程导致产品缺陷举例因作业过程导致产品

5、缺陷举例Stopper rods not protected with refractory paint塞杆上面没有刷保护涂层Pouring done with leaking nozzle.用漏水的钢包进行浇注Slide No. 8 J.VierimaaExample of workmanship因作业过程导致产品缺陷举例因作业过程导致产品缺陷举例Broken drying hoses in use; hot air leaking out; not going into the mould烘干炉的管子已经破损，热气在进入砂型之前就已经跑掉了。No dead end brick; all t

6、he dirty would go into the mould cavity没有放积渣槽，所有的渣滓会进入到型腔内。Slide No. 9 J.VierimaaExample of workmanship因作业过程导致产品缺陷举例因作业过程导致产品缺陷举例Pouring done with leaking nozzle用漏水的钢包进行浇注Pouring cup not protected during coating刷涂料的时候没有将浇口杯盖起来Cores not supported; bending, dimensional problems in castings砂芯没有支撑好。发生变形

7、，导致浇注之后的尺寸问题。Slide No. 10 J.VierimaaDiagnosis of casting defects 铸件缺陷的分析铸件缺陷的分析Do diagnosis 分析- Position of defect 缺陷的位置- Casting traceability 铸件的可追溯性- Process parameters in production 生产过程的工艺尺寸Correct diagnosis is essential, because it dictates the corrective actions 正确的分析至关重要，它决定采取正确的行动。Cure for o

8、ne defect can be the cause of another 消除一个缺陷采取的措施可能是导致另一种缺陷产生的原因。Confirmatory tests are important 验证试验非常重要。Slide No. 11 J.VierimaaDiagnosis of casting defects 铸件缺陷的分析铸件缺陷的分析Some Universities and Reaseach Centres have SEM- ( Scanning Electron Microscopy ) and EDS- ( Energy Dispersive X-ray Spectrosco

9、py ) equipments they can analyse inclusions and help to find right diagnosis 有些大学和研究中心拥有标准电子微缩设备（SEM）和能源扩散X光分光镜检查设备（EDS）分析杂质成分和提供正确的分析In European no-bake steel foundries the internal scrap ratios are around 1,5-2,0 %, customer scrap ratio 0,5 % and usage of welding consumables 2 kg / t 在欧洲，采用自硬工序的铸钢

10、厂中，内部的报废率约为1.5%至2.0%，客户端的报废率小于0.5%，焊材消耗率小于2公斤/吨。Slide No. 12 J.VierimaaChemical composition of the surface defects缺陷表面的化学成分缺陷表面的化学成分The use of Scanning Electron Microscope (SEM) is very helpful to find out the analysis of the surface defects of a casting. The main components of the chemicalanalysis

11、show the origin of the defect: 使用电透镜可有效分析铸件表面的缺陷，通过主要成分可找到缺陷的源头。Al2O3 + SiO2 (approx. 1:2) refractory fire clay material ( = gating system) 三氧化二铝+二氧化硅（大约为1:2）.耐火粘土物(浇铸系统)CaO + M-oxides . . slag from the ladle 氧化钙+合金氧化物 . 来自钢包的渣ZrO2 + SiO2 + Me-oxides Coating 氧化锆+氧化硅+合金氧化物 涂料 SiO2 and/or Cr2O3/Fe2O3

12、. sand erosion 氧化硅和(或)三氧化二铬/三氧化二铁 冲砂Al2O3, SiO2, MnO , Fe2O3 high oxide content in the steel 三氧化二铝，二氧化硅，氧化锰，三氧化二铁 . 氧化物含量过高。Slide No. 13 J.VierimaaSources for macroinclusions / SFSA产生杂质的几个主要源头产生杂质的几个主要源头/SFSAMain reasons for reoxidation 二次脱氧的主要原因二次脱氧的主要原因-throttling in pouring 浇注间断，不连贯-wrong gating

13、ratios 浇注系统设计比例不合理-ladle and pouring basin not in line 钢包出水口浇注时不对齐浇口。Slide No. 14 J.VierimaaDefects in sand cast ( no-bake ) steel castings （自硬式）砂铸钢的缺陷 - Common castings defects 常见铸件的缺陷常见铸件的缺陷- Causes 原因原因- Prevention 预防措施预防措施Slide No. 15 J.VierimaaSurface related defects in sand castings砂铸产品的外观缺陷砂铸

14、产品的外观缺陷Cold crack 冷裂缝冷裂缝Crack ( not oxidized ) in cold cast metal due to high internal residual stresses caused by由于内部残余应力过高产生冷裂，原因是：-Unsuitable casting design 铸件设计不合理-Rough handling 野蛮装卸/搬运-Restricted metal contraction 铸件收缩受阻-Improper heat-treatment procedure 热处理工艺不当Prevention 预防-Handle castings wi

15、th care 搬运工厂中要特别小心-Minimize flash around mould joints and core prints ( flash = acts like cooling rib or chill )-将砂型和芯头连接处的披凤最小化（披凤=起冷铁和冷却拉筋的作用）-Ensure good mould breakdown properties, use less binder in sand, use hollow cores 确保良好的脱模性，使用较少的树脂，空心化砂芯-Prevent stress raisers surface defects ( = startin

16、g point for crack )防止应力提升-表面缺陷（=开裂点）-Reduce residual casting stresses by new design, use progressive section thickness changes-采用新设计以减少铸件的残余应力，采用渐变壁厚。-Check the metal raw materials; avoid sulphur ( S ), phosphor ( P ), carbon ( C ) 检查原材料：避免含硫、磷和碳Slide No. 16 J.VierimaaSurface related defects in sand

17、 castings 砂铸产品的外观缺陷砂铸产品的外观缺陷Cold lap 冷隔冷隔Marks on the casting skin in the form of wavy folds which in some cases show the direction of the liquid metal flow. 铸件表面有波纹状的痕迹，有时痕迹表明钢液流动的方向。-Inadequate or badly designed gating system 浇注系统设计不良-Too thin wall thickness-design 铸件壁厚设计过薄-Pouring temperature too

18、 low 浇注温度过低-Interrupt / bad pouring 浇注间断/不当-Pouring with leaking nozzle用漏水的出水口浇注-Ladle not in-line above pouring cup钢包和浇口杯未对齐Prevention 预防预防-Use well designed gating system, avoid turbulence ( steel flow 25 kg / s ) 尽快浇注，无间断（大于25）-Check the gating ratios ( bottom pouring 1:2:4:4 )检查浇注系统的通道比例（底注式1:2:

19、4:4）-Pour the moulds “ uphill “ or thin castings on vertical position.那些向上的砂型或较薄的铸件需要在垂直的位置进行浇注-If too thin design add thickness and / or fins 如果设计过薄增加尺寸厚度-Increase pouring temperature 提高浇注温度-Avoid high residual aluminium ( Al ) in de-oxidation, increase silicon ( Si ) 避免脱氧时残余铝过高，增加硅含量Slide No. 17 J

20、.VierimaaSurface related defects in sand castings 砂铸产品的外观缺陷砂铸产品的外观缺陷Sand burn-in烧砂烧砂A fused layer of sand adhering firmly to the surface of the casting, particularly in thick metal sections or where thin sections of mould or core are surrounded by metal铸件表面牢牢粘附一层已烧化的砂,特别是铸件较薄部分或者模和芯环绕的较薄的部分。-Poor co

21、mpaction.舂砂不严实-Impurities in silica sand ( CaO, K2O, Na20 ).硅砂里面有杂质Contamination of sands by iron oxide etc 氧化物致使砂受到污染-Poor coating quality and practice 刷涂层操作不当-Too high pouring temperature 浇注温度过低Prevention 预防预防-Use higher quality silica sand ( SiO2 minimum 98-99 % ) 使用高质量的硅砂（二氧化硅）-Check the sulphur

22、 ( S ) content of the reclaim sand; ought to be 25 kg / s ) 尽可能使用最低的浇注温度；保持较好的钢液流动性（大于25千克/秒）-Modify gating system, avoid hot spots 修改浇注系统，避免出现热节Slide No. 18 J.VierimaaSurface related defects in sand castings砂铸产品的外观缺陷砂铸产品的外观缺陷Prevention 如何预防如何预防-Ensure sand to sand contact on parting line 确保合模良好，在分型

23、线中无缝隙-Repair the damages of flasks ( add sand retaining ribs, clean flask joint faces etc ) 修补砂箱（ ）-Use rigid bottom boards and check the flatness of the patterns 使用刚性底板，并检察平整度-Support the cores in storage 砂芯在存放过程中放置支撑-Avoid excessive coating of core prints 芯头勿涂过多涂料-Use minimum fillets around the co

24、re prints 使用芯头无尖角、边的的砂芯-Ensure adequate weighting / clamping prior to pouring 浇铸前确保适当地重量和夹紧-Check that the floor is straight and better to have some layer of sand on it 检查地面平整是否，最好有层砂Flash 披凤披凤Projections in the form of metal wafers of varying thickness occurring at mould joints, around core prints

25、or between mould and core joints.钢液在分型线溅出，在芯头或者上下模和芯之间形成不均的薄片-Damaged moulding boxes 损坏模具盒-Lack of reinforcing bars in flasks 砂箱中未放置加强筋-Incorrect seating of cores in prints 芯头放置不正确Slide No. 19 J.VierimaaSurface related defects in sand castings砂铸产品的外观缺陷砂铸产品的外观缺陷Hot tear 热裂热裂Tear occurring during soli

26、dification process, distinguished from a cold crack by an oxide skin at its crack surface. 铸件在固化过程中出现了热裂，与冷裂的区别是热裂缝表层有一层氧化的表层-Restraint to contraction by the mould / core 限制砂模/砂芯的收缩-Poor design of casting 浇注系统设计不恰当-Premature shake-out 震砂过早-High pouring temperature 浇注温度过高Prevention 预防预防-Modify castin

27、g design to avoid heavy sections; add several ingates 修改铸件设计；增加内浇道-Avoid sharp corners, hot spots, chaplets ( = starting point for cracks ) 避免尖角、热节、使用芯撑（裂缝的始点）-Ensure good mould breakdown properties, use less binder in sand, use hollow cores 确保震砂性能，减少使用树脂，使用空心砂芯-Use phenol resin binders instead of s

28、odium silicate or furan 使用苯酚树脂代替硅酸钠或者呋喃-Use low pouring temperature but high flow volume ( 25 kg / s ) 降低浇注温度但增加钢水流动速度-Let the castings cool down in the sand 铸件在砂中冷却到一定的温度-Have the ferrite content below 50 % in super-duplex steels 在超级双相钢中铁素体的含量小于50%Slide No. 20 J.VierimaaSurface related defects in s

29、and castings砂铸产品的外观缺陷砂铸产品的外观缺陷Metal penetration 钢液渗透钢液渗透A agglomerated layer of sand grains and metal mechanically jointed to the casting surface. 在铸件表面产生一层砂和金属机械地黏在一起-High ferrostatic pressure due pouring from high ladle position 在浇注时钢水静压力过高-High dynamic pressure due to flow characteristics 由于钢液流动特

30、性，动态压力过高-High sulphur ( S ) content in reclaim sand再生砂的硫含量过高-Poor compaction 舂砂不严实-Poor coating涂料没有刷好Prevention 如何预防如何预防-Check the sieve analysis; more than 80 % in 3-4 sieves, average sand grain size around 0,30 mm检查砂子筛选分析：80%以上的砂应该分布在3-4个筛子里面，砂子的平均粒度是0.30mm-Do good compaction of the cores and moul

31、ds 加强砂模和砂芯舂砂严实-Check the viscosity of the coating; use thicker coating检查涂料的浓度，使用更浓的涂料-Use smaller ladle 使用较小的钢包-Check the gating ratios ( bottom pouring底注式 1:2:4:4 ) 检查浇注系统比例-Use well designed gating system, avoid turbulence ( steel flow 38 % Al2O3 ) raw material for ceramic gating tubes 陶瓷浇道管的原材料中铝

32、含量要高( 38 % Al2O3 ) -Shot-blast the return scrap no sand or ceramics into the furnace ( = reduces also lining lifetime )报废的回炉料需要抛丸 不要将砂子或陶瓷片混到电炉中（=这材质缩短炉龄）-Use male-female connections and masking tape in ceramic tubes 陶瓷管使用公母连接方式和不透光胶纸-Protect ceramic gating systems during coating; use plugs in flow

33、coating 上涂层时要保护陶瓷浇注系统，流涂要塞住浇口杯-Grind sharp corners away from the cores during assembly and cover ready moulds 合箱时磨去砂芯的尖角Slide No. 23 J.VierimaaSurface related defects in sand castings砂铸产品的外观缺陷砂铸产品的外观缺陷Finning / Veining 脉纹脉纹Thin, rough and irregular fins of metal projecting from the casting surface;

34、most often in corners ( impeller castings ! ) 在铸件的外观可以发现有一些薄的、粗糙的、不规则的鳍装物。常见于转角处（叶轮铸件）-Silica sand expansion 硅砂扩张-Too high sand compaction (core-shooter! ) 砂过于紧实（射芯机）-Sharp corners 尖角-High pouring temperature 浇注温度过高Prevention 预防预防-Use right ratios of resin:hardener in sands; dont over-cure 使用正确的树脂、固

35、化剂比例，不能过量调整-Use as low as possible shooting pressures in core-shooter; 3 bars. 射芯机压力尽可能的低一些， 25 kg / s ) to minimize radiation time 增加钢液流动量( 25千克/秒)减少放射时间Slide No. 24 J.VierimaaSurface related defects in sand castings砂铸产品的外观缺陷砂铸产品的外观缺陷Misrun 浇不足浇不足Part of the casting is missing usually on the cope s

36、urface. The edges adjacent to the missing parts are rounded and generally shiny. 浇不到的地方，边比较圆通常会发光-Pouring temperature too low 浇注温度过低-Pouring too slow 浇注速度慢-Slag on metal surface 金属面有炉渣-Interruptions in pouring 间断浇注-Ladles nozzle and pouring cup not in-line during pouring 浇注过程中钢包出水口和浇口杯没有对齐Prevention

37、 预防预防-Increase pouring temperature and flow ( 25 kg/s ) 提高浇注温度和钢液流动性-Dont pour over 25 moulds with the same ladle and 10 impeller moulds with one ladle不要用同一包水浇铸超过25箱铸件，同一包水也不能浇注超过10个叶轮-Modify the metal composition to add the fluidity; e.g in C-steels less Al in de-oxidation 修改钢液成分；例如含碳钢中环氧中减少铝含量-Rem

38、ove the slag from metal surfaces 去除钢液表面的熔渣-Dont interrupt the pouring 勿间断浇注-If throttling check the gating ratios ( 1:2:4:4 ) 如果出现节流检查浇注通道比例-Add dirty traps and air pins 增加集渣槽和排气棒-Have at least one open feeder and good venting最少保证有一个明冒口和通气良好Slide No. 25 J.VierimaaSurface related defects in sand cast

39、ings砂铸产品的外观缺陷砂铸产品的外观缺陷Erosion, wash 腐蚀，洗涤腐蚀，洗涤Projections on the casting surfaces in positions where metal flow hits onto the mould / core surface ( sand inclusion ) 注射的钢液冲刷砂型/砂芯表面，产生夹砂。-High metal velocity 钢液流动速度过快-Wrong place for ingates 内浇道设计位置错误-Inadequate sand properties 砂性能不当-High metal throug

40、hput 金属吞吐率过高Prevention 预防预防-Modify the gating system to reduce concentration of metal flow 修改浇注系统，减小钢液流动的集中性-Use thicker coating or higher refractory sands ( = ceramic, chromite ) in washed areas在被冲走的区域使用更厚的涂料和耐高温的砂（陶瓷砂和铬矿砂）-Reduce metal velocity in ingates ( 38 % )将浇道系统更换为陶瓷管（Al2O3 含量 38 % )-Use sm

41、aller ladles使用更小的钢包Slide No. 26 J.VierimaaStructure related defects in sand castings砂铸产品的结构不良砂铸产品的结构不良Gas blowholes 皮下气孔皮下气孔Cavities occurring at or near casting surface, spherical or elongated and generally having smooth or rounded walls. -Moisture in raw materials 原材料有水分-High humidity 湿度过高-Entrapp

42、ed air 空气堵塞 -Entrapped gases 气体堵塞-Fresh cores, moulds not dried 新砂芯、砂型未充分干燥-High L.O.I in reclaim sand 再生砂的烧损量过高Prevention 预防预防-Dry all the raw materials ( sand, refractories, feeder sleeves, limestone, scrap etc )烘干原材料（砂子、耐火材、冒口、石灰石、废品等）-Check the de-dusting, sand reclamation system, binder level a

43、nd usage of new sand to reduce L.O.I 1,0%检查除尘系统、砂再生系统、树脂使用量和新砂使用量将烧损量降低到1.0%。-Avoid sharp corners in casting design; super heated core / mould area produces a lot of gas在铸件设计时避免锋利边角，砂芯和砂型的过热产生大量的气体。-Check the feeding system ( = shortage of feeding; under pressure inside the casting favors gas defect

44、s)检查浇注系统（=浇注不够、铸件内部带压会导致气体不良）-Avoid turbulence in gating system ( = metal speed 0,5 m / s, proper ratios 1:2:4:4 )、避免浇注系统中出现湍流（钢液流动速度小于0.5米/秒，比例1:2:4:4）-Avoid throttling in pouring 浇注中避免节流 -Increase pouring temperature 升高浇注温度-Do venting holes to cope mould, add venting to cores and have at least one

45、 open feeder 在上模上面打通气孔，砂芯上面加通气塞并保证最少有一个明冒口-Pour the dried moulds asap to avoid condensation 应尽快对已烘干的砂型浇注以避免冷凝-Check the core print dimensions and the usage of glue / cope seal.检查芯头的尺寸、粘胶、油封条的使用情况Slide No. 27 J.VierimaaStructure related defects in sand castings砂铸产品的结构不良砂铸产品的结构不良Hydrogen pinholes 氢气针孔

46、氢气针孔Small spherical holes just below the casting surface. The holes are often smooth and shiny. 在铸件表面下微小的球状孔。小孔平面一般比较光滑，明亮-Low pouring temperature 浇注温度低-Improper de-oxidation 脱氧不良-Moisture in raw materials 原材料含有水分-Wet moulds / cores 砂模、砂芯含有水分Prevention 预防预防-Dry all the raw materials ( sand, refracto

47、ries, feeder sleeves, limestone, scrap etc ) 烘干所有的原材料（砂子、 耐火材、冒口袖、石灰石和废品等）-Dry all the patchings 烘干所有的修补材料-Use protective slag during melting, avoid high melting temperatures, avoid holding the ready melt 熔炼时使用保护渣、避免高温熔炼、避免长时间炉内放置.-Use AOD refining and Argon purging in the ladles使用AOD炉并往钢包内吹氩气-Incre

48、ase pouring temperature 升高浇注温度-Avoid long gating systems 避免浇注温度过长-Use CaSi in de-oxidation instead of aluminium ( Al ) 在脱氧中使用硅化钙代替铝-Dont use fresh cores and dry moulds long enough不要使用新的砂芯，并充分烘干砂型-Use iron oxide in Cold-Box core sand ( Fe2O3 about 2-5 % weight of the sand ) 在冷芯盒砂芯那里使用氧化铁（ Fe2O3 的重量占砂

49、重量的2-5%）Slide No. 28 J.VierimaaStructure related defects in sand castings砂铸产品的结构不良砂铸产品的结构不良Nitrogen pinholes and fissures氮气气孔氮气气孔Bright smooth faced surface or sub-surface irregular shaped cavities ( = fissure ) or spherical cavities ( = nitrogen pinholes ) in thick sections. 气孔表层平整明亮；在较薄的部分的表层下有不规则

50、的孔或者球状孔-Excess nitrogen in scrap 回炉料中含氮量过高-High nitrogen sand binders 树脂中含氮量过高-Poor sand reclamation 砂回收系统运转不良Prevention预防预防-Use only low nitrogen binders and coatings in sand 使用氮含量较低的砂和树脂-Avoid scrap materials with high nitrogen 不使用氮含量过高的回炉料-Check the nitrogen analysis of the spectrometer; combusti

51、on method gives accurate values. 用光谱仪检查氮元素，燃烧的方法测试的值更加精确-Have nitrogen in duplex- and super duplex steels on the low side.双面不锈钢和超级双面不锈钢的氮含量应该要偏低-Check sand reclamation system, de-dusting and the usage of the new sand; keep Loss of Ignition 1.0 %检查再生砂系统，除尘系统和新砂的使用量，保证烧损值低于1.0%。-Dont use fresh Cold-Bo

52、x cores; they should be minimum 24 h old .不要使用新的冷芯盒，最少要放置24小时再用。-Cold-Box phenol resin ( Part I) and isocyanate ( Part II ) should be mixed with 1:1 ratio or use the ratio 55:45 to reduce the risk of gas defects ( Isocyanate contains plenty of nitrogen )冷芯盒酚醛树脂I和异氰酸盐II需要按照1:1或55:45的比例来配兑使用，这样可以降低气体不

53、良的风险。-Use FeTi as a de-oxidation material in C-steels to neutralize nitrogen 在碳铁中，使用钛铁为脱氧材料抵消氮。Slide No. 29 J.VierimaaStructure related defects in sand castings砂铸产品的结构不良砂铸产品的结构不良Shrinkage / Porosity 缩孔缩孔/缩松缩松Cavities of varying size. Quite often a dendritic structure is evident. The defects occurs i

54、n the last metal to solidify or in centre line.各种形状的孔。常见的是树枝形状。此缺陷出现在钢液最后凝结的部分或者在铸件的中心线部位-Poor casting design 铸件设计不良-Lack of sufficient feed metal 补缩不畅-High pouring temperature 浇注温度过高-Soft mould 砂型硬度不够Prevention预防预防-Use AOD refining and Argon purging in ladles to reduce the gas contents.使用AOD精炼炉并在钢包

55、内吹氩气来降低气体含量。-Do filling and solidification simulation with Magmasoft program用迈格玛软件模拟充填和凝固过程。-Re-design the casting or use paddings, different casting position etc 重新设计铸件或者增加补贴-Check the modulus of the casting : feeder neck : feeder ( should be 1 : 1,1 : 1,3 ). 检查模数：铸件：冒口座：冒口的模数（应该是1:1.1:1.3）-Check f

56、eed volume requirements ( important while using high exothermic feeder sleeves ) 检查冒口的容积要求（使用高吸热冒口袖的话，这个因素非常重要）。-Reduce the pouring temperatures; e.g 1500 C is enough for heavy section 1.4460 duplex steel 降低浇注温度，如：1.4460双相不锈钢较厚截面，1500度的温度就已经足够。-Use chills or chilling sand like chromite in hot spots

57、热节部位使用冷铁或有冷却作用的砂如铬矿砂-Have support ribs in flasks and extra steel bars top of flat castings like Kaplan blades to reduce the mould movement 给砂箱加加强筋、在砂箱顶部加钢条（如轴流转刀片来降低砂型的移动）Slide No. 30 J.VierimaaWorkmanship related defects in sand castings 操作操作致砂铸产品缺陷致砂铸产品缺陷Leakage from the mould 跑火（砂型漏水）跑火（砂型漏水）Moul

58、d is leaking during pouring or immediately after the pouring. 浇注过程中或浇注之后，砂型立马发生漏钢问题。Casting is only partly full or has discontinuation marks.铸件只是部分浇满或有中断痕迹-Too narrow free parting line or mould height too small 活动的分型线太窄或砂型的高度太低-No cope seal or adhesive on parting line 在分型线没有放泥条或其他的粘结材料-Not enough cl

59、amps or no clamps at all 夹子不够或根本没有打夹子-Mould strength too low 砂型的强度太低-No support bars / sand ribs on the flasks or support bar across 没有支撑块或砂箱内没有足够多的支撑故为，没有交叉支撑骨位-Mould is placed on uneven floor 砂型没有放置在平整的地面上Prevention预防措施预防措施-Have minimum 30 mm sand on parting line and 50-100 mm under the lowest par

60、t of the mould cavity在分型面最少需要30mm的砂，在砂型型腔最低的面有50-100mm的砂。-Have at least one open feeder and venting to reduce the ferrostatic pressure during filling.最少有一个明冒口和通气孔来减少浇注过程中型腔内的压力-Have clamps enough and especially near the connection of downsprue and runner bar配置足够的夹子，特别是在浇口杯和横浇道附近。-If youll hang the c