BS5135-84WeldQuality.doc

BS 5135:1984 Table 18Guidance on acceptance levels for butt joints (對接接頭驗收標準指引)Notation (標誌) : T母材厚度, L缺陷長度, H缺陷高度, W缺陷寬度. P. 46質量標準類別Category-ACategory-BCategory-CCategory-D測定體積的無損探傷最少量100%每個焊工10%*總体10%*僅作100%外觀檢查不作其它無損檢測裂紋不允許不允許不允許不允許未熔合不允許T20mmL10mmH2mm在焊縫任意100mm長度上, L25mm或H1.5mmL25%焊縫長度根部未熔合T20mmL15mmH2mm只在焊縫接頭一面執行單個夾渣T18mmLT/218mm75mmLT/3W1.5mmT20mmL20mmW1.5mmT75mmL25mmW1.5mm線狀夾渣群線狀夾渣群總長度不超過12T而單組長度總長的8%線狀夾渣群可為任意長，但規定相鄰線狀夾渣之間距離。當T20mm時，距離最少是最長缺陷的4倍，若T20mm時則為6倍。線狀夾渣群可為任意長，但規定相鄰線狀夾渣之間距離最少是最長缺陷的4倍不合適氣孔群單個氣孔E2mm單個氣孔E2.5mm單個氣孔E3mmE0.25T單個表面氣孔E3mmE0.25T局部氣孔群當T50mm時面積2% 當T50mm時面積按比例增加局部氣孔群面積3% 局部氣孔群面積4% 局部氣孔群面積4% 咬邊斷續咬邊最大深度0.5mm斷續咬邊最大深度0.5mm斷續咬邊最大深度0.5mm深度0.1T1mm L10%的焊縫長度BS 5135: 1984 Table 18 P.46* 當 “測定體積的無損探傷” 隨機抽檢揭露出在一個接合焊縫中有不及格的缺陷時，另兩個在此組(類,群)構件中相若的接合焊縫將需以類似探傷手段加驗。若這兩個另外加檢接頭的探傷結果及格，則原來的不及格焊縫將需翻修及以同樣探傷手段復驗。如翻修質量令人滿意，此組(類,群)構件的接合焊縫將可及格。若這兩個另外加檢接頭的探傷結果不及格，每一個此組(類,群)構件中的接合焊縫將需執行無損檢測。不及格的缺陷必須翻修及以同樣探傷手段復驗。 這並不意味著整個接合焊縫不及格，僅是給予特定地區加以處理(關注)，例如：局部修理或打磨而無需補焊。 在進行超聲波檢驗時發現這類缺陷，還必須採用放射線探測再加以檢查。 此面積必將被視為受氣孔群所影響焊縫的長度倍於其最大寬度。 BS 5135:1984 Table 19 Guidance on acceptance levels for fillet welds (角焊縫驗收標準指引) P.47質量標準類別Category-ACategory-BCategory-CCategory-D表面的無損探傷最少量 (液體滲透或磁粉探傷任一種)100%的焊縫表面及每側相鄰各10mm的母材金屬隨機抽檢10%的焊縫表面及每側相鄰各10mm的母材金屬隨機抽檢5%的焊縫表面及每側相鄰各10mm的母材金屬僅作100%外觀檢查，不作其它無損檢測裂紋、未熔合不允許*不允許*不允許*不允許*咬邊斷續咬邊最大深度0.5mm斷續咬邊最大深度0.5mm斷續咬邊最大深度0.5mm一些咬邊最大深度1mm裝配對於半(部分)熔透T-形接頭，坡口預備及裝配的檢查結果應被記錄焊喉厚度總體的焊喉厚度不可少於說明* 這並不意味著整個接合焊縫不及格，僅是給予特定地區加以處理(關注)，例如：局部修理或打磨而無需補焊。 如發現裂紋或未熔合，那裡可能需要執行高達100%的檢驗。 咬邊的可容許性必將由設計師偕同顧問公司(在監管下)的承包商質檢部門和任何(參予的)檢驗機構共同斟酌。BS 5135:1984, Clause 27. Quality of welds27.1 Welded joint shall be free from defects that would impair the service performance of the construction. Such acceptance requirements, covering both surface and subsurface defects, shall be in accordance with the application standard where it exists.27.2 If no application standard exists, acceptance requirements shall be agreed between the contracting parties.Note: When no application standard exists which specifies acceptance criteria, the guidance given in Appendix H may be used to facilitate agreement between the contracting parties on the requirements to be met.Appendix H Guidance on acceptance levelsTo facilitate agreement between the contracting parties where no acceptance levels are specified in an application standard, the arbitrary levels given in tables 18 and 19 may be used for guidance, bearing in mind that a standard higher than quality category A may be essential for fatigue situation in butt joints when surface grinding of welds may be required.These quality categories relate to individual joints, not the complete fabrication.It is emphasized that the consequences of failure in service of the particular welded joint in a structure should be the essential basis for deciding which quality category to use and the extent of appropriate non-destructive testing, taking into account whether the weld is designed as a partial-penetration joint.In general, defects buried within the inner half of the cross section of a joint are less significant than those in the outer quarters, a feature which should be borne in mind when considering rejection of joint that appear to be borderline.Although arbitrary, these categories have been applied successfully in practice and are based on other British Standards as fallows:Quality Category A: Similar to the level required for (BS 4870: Part 1 & BS 4871: Part 1)Quality Category B: Class I welding (BS 2633)Quality Category C: Class II welding (BS 2971)Quality Category D: Similar to the level required for general purpose welders when there is no approval of procedures (BS 4872: Part 1)Note: There is no relationship between the letter designations for quality categories and those used for hydrogen scales.Profile defects表面形態缺陷(a) Undercut咬邊Slight intermittent undercut permitted, depth not to exceed approximately 0.5 mm輕微地間斷的咬邊可以允許，深度不可超過0.5mm(b) Shrinkage grooves and root concavity焊溝縮陷和根部凹陷As for undercut, but depth not to exceed 1.5 mm如咬邊，但深度不可超過1.5mm(c) Excess penetration過分熔透h 3 mm. Occasional local slight excess is allowableh 3mm，偶然存在緊僅超過規定亦可容許(d) Reinforcement shape餘高輪廓The reinforcement is to blend smoothly with the parent metal; dressing is not normally required provided the shape does not interfere with the specified non-destructive testing techniques餘高要與母材平順地融合，若不影響(指定執行的)無損檢測技術一般不要求提供(表面)修飾(e) Overlap焊瘤(堆覆)Not permitted不允許(f) Linear misalignment不值線(歪扭)h t /10, 3 mm maximumh t/10，最大值3mm* For definitions of defect types, see BS 499: Part 1. ! In assessing porosity the area of radiograph to be considered is the length of weld affected by the porosity times the maximum width of the weld. ! Individual inclusions within the group should not exceed the sizes for isolated pores (or individual pores In a group). A linear group is defined as a number of inclusions in line and parallel to the weld axis where the spacing between their adjacent ends does not exceed 6 times the length of the longest inclusion within the group. With parallel groups, all inclusions count towards the aggregate. NOTE. The significant dimension of a defect in terms of its effect on service performance is the height or through thickness dimension. If ultrasonic examination is em