NAVY MIL-W-21157 A-1971 WELDMENT STEEL CARBON AND LOW ALLOY (YIELD STRENGTH 30 000-60 000 PSI)《生产强度30000-60000PSI低碳合金钢焊件》.pdf

《NAVY MIL-W-21157 A-1971 WELDMENT STEEL CARBON AND LOW ALLOY (YIELD STRENGTH 30 000-60 000 PSI)《生产强度30000-60000PSI低碳合金钢焊件》.pdf》由会员分享，可在线阅读，更多相关《NAVY MIL-W-21157 A-1971 WELDMENT STEEL CARBON AND LOW ALLOY (YIELD STRENGTH 30 000-60 000 PSI)《生产强度30000-60000PSI低碳合金钢焊件》.pdf（25页珍藏版）》请在麦多课文档分享上搜索。

1、d . MIL-W-23357A TH 7799906 0453523 7-m- “ _=_= =- - “ MIL-W-21157A (OS) 26 October 1971 SUPERSEDING MIL-W-21157 (NORD) 29 November 1957 (See Section 6) MILITARY SPECIFICATION WELDMENT, STEEL, CARBON AND LOW ALLOY (YIELD STRENGTH 30,000-60,000 PSI) mis specification has been approved by the Naval Or

2、dnance Systems Command,Department of the Navy. 1. SCOPE 1.1 Scope. This specification covers the requirements for steel weldments fabricated by metal electrode welding processes. 1. 2 Classification. Weldments shall be of the following classes, as specified (see 6. 2 and 6.3 and tables I-A and I-B).

3、 Class 1 Class 2 Class 3 Class 4 Class 5 2. APPLICABLE DOCUMENTS 2.1 The following documents of the issue in effect on the date of invitation for bids or request for proposal, form a part of this specification to the extent speci- fied herein: SPECIFICATIONS Federal QQ-E-450 Electrode, Wlding, Cover

4、ed, Mild Steel r . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-W-21157A (OS) Military MIL-1-6868 MIL-1-8950 MIL-R-11468 MIL-R-11469 MIL-R-11470 MIL-”11473 MIL-E-18038 MIL-E-22200/1 STANDARDS Military MIL-STD-22 MIL-STD-105 MIL-STD-129 MIL-STD

5、-130 MIL-STD-163 MIL-STD-248 MIL-STD-410 MIL-STD-453 Inspection Process, Magnetic Particle Inspection, Ultrasonic, Wrought Metals, Process for Radiographic Inspection, Soundness Requirements for Arc and Gas Welds in Steel Radiographic Inspection, Soundness Requirements for Steel Castings Radiographi

6、c Inspection, Qualification of Equipment, Operators and Procedures Magnetic-Particle Inspection, Soundness Require- ments for Weldments Electrodes, Welding, Mineral Covered, Low Hydrogen, Medium and High Tensile Steel as Welded or Stress Relieved Weld Application Electrodes , Welding, Mineral Covere

7、d, Iron- Powder, Low-Hydrogen Medium and High Tensile Steel, as Welded or Stress Relieved Weld Application Welded Joint Designs Sampling Procedures and Tables for Inspections by Attributes Marking for Shipment and Storage Identification Marking of U, S. Military Property Steel Mill Products, Prepara

8、tion for Shipment and Storage Qualification Tests for Welders Qualification of Inspection Personnel (Magnetic Particle and Penetrant) Inspection, Radiographic 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.* c . I, . MIL-W-21157A (OS) Federal FED

9、-STD-151 Metals: Test Methods (Copies of specifications , standards , drawings , and publications required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer. ) 2.2 Other publications. The following

10、documents form a part of this specifi- cation to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal shall apply. American National Standards Institute ANSI Y14.5 Dimensioning and Tolerancing for Engineering Drawings ANS

11、I Y32.3 Welding Symbols (Application for copies should be addressed to the American National Standards Institute, 1430 Broadway, New York, N, Y. 10018. ) American Welding Society AWSA-2.2 Nondestructive Testing Symbols AWSA- 3. O Definitions - Welding and Cutting (Application for copies should be ad

12、dressed to the American Welding Society, 345 East 47th Street, New York, N. Y. 10017. ) . American Iron and Steel Institute Steel Products Manual (Application for copies should be addressed to the American Iron and Steel Institute, 150 East 42 Street, New York, N. Y. 10017. ) Steel Founders Society

13、of America Steel Casting Handbook (Application for copies should be addressed to the Steel Founders Society of America, 21010 Center Ridge, Cleveland, Ohio 44113. ) 3. REQUIREMENTS 3.1 Capabili. Peening shall be accomplished with a round or blunt nosed tool. Such mechanical work shall be performed i

14、n a manner that will not tear or burr the peened area. Care must be taken that all surface slag, slag inclusions, gas holes, or folds are removed from the weld before peening so that no foreign material or unfused area will be embodied in the weld. Peen- ing should preferably be done at temperatures

15、 not exceeding 500“ F, at a travel rate of 20 inches per minute with a medium hammer. 3.14.3 Restrictions. 3.14.3.1 Weldments not subsequently heat treated. Peening shall not be done on single layer fillet welds but may be done on all but the first and last 8 - Provided by IHSNot for ResaleNo reprod

16、uction or networking permitted without license from IHS-,-,-MIL-W-21157A (OS) layers of multiple layer fillet welds. Peening shall not be done on the first two layers or the last layer of single or double bevel , “Uw, or J groove welds. 3.14.3.2 Weldments subsequently heat treated. For weldments whi

17、ch will be subsequently stress relief annealed, peening may be done on any weld layer. Care must be taken on first pass layers not to crack the weld due to the reduced section in which work is being accomplished. The soundness of heavily peened first pass welds should be demonstrated by magnetic-par

18、ticle inspection before subsequent. passes are applied. 3.14.4 Damage to parent metal. Care shall be taken not to damage or reduce the cross sectional area adjacent to the weld with the peening tool. 3.15 Weldment temperatures. 3. 15.1 Ambient temperature. Tack welding or production welding of any k

19、ind shall not be done when the ambient atmospheric and material temperature is less than 60“ F. 3.15.2 Preheat temperatures. When not otherwise specified in the applicable drawings, sufficient preheat shall be used to avoid cracking, control distortion, and otherwise to ensure sound welds. 3.15.3 He

20、avy sections. Heavy welded sections shall be welded continuously, that is, once welding has been started on a joint, the welding operation shall be continued until completed, 3.15.4 Straightening. Where appreciable straightening or forming is re- quired, the weldment may be locally preheated. This p

21、reheating shall not exceed 1150“ F unless subsequent corrective heat treatment is employed. 3.16 Size and shape of welds. 3.16.1 Size. The form and dimensions of the welds shall be in accordance with the applicable drawings except as specified in 3.13.1. Weld sizes given on the drawings shall be con

22、sidered the minimum size when measured in accor- dance with AWSA-3. O, Fillet weld sizes shall not exceed the next 1/16-inch larger size for welds up to three-eighths inch. For welds three-eighths inch and larger, the size shall not exceed the next 1/8-inch larger size. Fillet weld sizes may be dete

23、rmined by the method sbpwn in figure 1 using the gage shown in figure 2. 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-W-ELL57A TH 9999906 0453530 B W MIL-W-21157A (OS) 1 r 10 . Provided by IHSNot for ResaleNo reproduction or networking permi

24、tted without license from IHS-,-,-“ MIJJ-W-2i157A (OS) FIGURE 2. BUTT AND FILLET WELD GAGE RIVET ING WASHER 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-W-2II57A TH W 779770b 0453532 I W MIL-W-21157A (OS) ,. , 3.16.2 Weld reinforcement, For

25、 plate one-half inch and greater in thickness the reinforcement of butt welds shall not exceed one-eighth inch except as speci- fied for individual joints on the applicable drawings. For material under one-half inch, the reinforcement shall not exceed 25 percent of the material thickness. 3.16.3 Fil

26、let weld form. Fillet welds having a concave face are desirable. Excessive convexity, as determined by the gage (figure 1) , may be corrected by grinding or chipping. 3.16.4 Length of fillet welds. The length of a correctly proportioned fillet weld, whether intermittent or continuous and exclusive o

27、f any craters and starts, shall be in accordance with the length specified on the applicable drawing. 3.16.5 Extension of fillet welds. Fillet welds shall extend around the ends of abutting members when practicable. 3.17 Undercut and overlapping welds. Undercutting or overlapping welds will not be p

28、ermitted except as specified in 4.2.3 for the applicable class of weldment. 3.18 Removal of reinforcements. Where butt welds which are to be finished flush occur on unmachined surfaces, the reinforcement shall be removed by chipping or grinding. Care shall be taken to avoid undercutting or nicking t

29、he surface of the plates in the vicinity of the welds. 3.19 Width of deposit. Welds may be built up by weave beads or by stringer beads, The width of the deposit shall not be greater than four times the nominal diameter of the electrode. 3.20 Stress relief annealing, When specified by the procuring

30、activity or applicable drawing, weldments shall be stress relieved after completion of all welding and straightening operations except as specified in 3.20.1. 3.20.1 Stress relief after minor repairs. Minor repairs of weldments may be made without subsequent stress relief annealing by excavating def

31、ective areas until clear of defects and rewelding the excavation while the area is locally pre- heated to 200“ - 400“ F provided that the area is so located that the resultant stresses will not cause the weldment to be dimensionally unstable during machin- ing or in service. An excavated weldment or

32、 a sketch showing the location of repairs and the dimensions of the excavations shall be submitted to the procur- ing activity prior to finish machining any part of the weldment to decide if stress relief annealing is necessary. Provided by IHSNot for ResaleNo reproduction or networking permitted wi

33、thout license from IHS-,-,-J ._ flIL-W-24L57ATHI 777770b 0453533 3 MIL-W-21157A (OS) .r 3.20.2 Annealing Procedure. The following procedure shall be used for strems relief annealing completed weldments or for any interim annealing that may be necessary on subassemblies and weldments in the course of

34、 repair: (a) Adequate supports shall be provided in the stress relief annealing furnace to minimize changes in the shape of the weldment due to its own weight or the weight of the charge. (b) The stress relief annealing furnace shall be equipped with adequate recording equipment and thermocouples in

35、 sufficient number attached to the charge and so located as to record accurately the temperature of the weldments- or annealing charge, Care shall be taken to see that the probable hottest and coolest point of the charge for both heating and cooling cycles is recorded. The temperature of the charge

36、shall be considered the mean between the highest and lowest reading. The maximum temperature difference between any two parts in the charge shall not exceed 100“ F, except as permitted under 3.20.2(f) during the heating or cooling cycle, or 50“ F during the soaking period. (c) The temperature of the

37、 furnace shall not exceed 105“ F plus the ambient temperature at the time the charge is loaded. The charge shall be heated to 1175“ F f 25“ at a rate not exceeding 150“ F per hour, except as permitted under 3.20.2(f). (d) When the charge has reached a mean temperature of 1175“ F f 25“, as specified

38、in 3.20.2(c), it shall be held within this temperature range for the minimum period of 1 hour for each inch or fraction thereof of maximum thickness of the weldment section, unless the holding time is otherwise specified by the procuring activity or applicable drawing. For thicknesses.less than 1 in

39、ch, the holding time shall be proportional to the thickness but not less than 30 minutes. (e) The charge shall be cooled in the furnace. The rate of cooling shall not exceed 150“ F per hour except as permitted under Y. 20.2(f). When the furnace has cooled to a temperature of 300“ F or less, the char

40、ge may be re- moved from the furnace and allowed to cool to ambient temperature in still air protected from moisture. (f) The heating and cooling rate of 150“ F specified in 3.20.2(c) and 3.20.2(e) may be exceeded if the furnace is such that a maximum temperature difference of any two points in any

41、weldment does not exceed 75“ F. 3.21 Straightening. 3.21.1 Progressive straightening. To avoid the necessity for major straight- ening of weldments, check measurements shall be made at frequent intervals during the course of fabrication. Corrective measures shall be taken concur- rently as required

42、rather than permitting warpage to accumulate for a final straightening, 13 - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-W-21157A (OS) 8. 3.21, 2 Stress caused by straightening, No excessive concentration of stress in any section of a weld or

43、 plate shall be created by straightening, Buckled or stressed sections may be relieved by opening welded seams and rewelding. Re- quests for the making of additional seams must be authorized by the procuring activity. Preliminary stress relief annealing may be performed on weldments prior to straigh

44、tening in order to reduce the possibility of rupturing the base metal or cracking the welds. 3. 22 Weldment finish. 3.22.1 Scale, All scale, oxides, and foreign material shall be removed from the weldment surface after stress relief annealing. 3.22.2 Rust prevention. Unless otherwise specified, the

45、weldments shall be protected against corrosion by coatings of paint, agreeable with the finish speci- fications given on the detail drawing of the part. Weldments received from the contractor shall be free from rust. The contractor shall be liable for the cost of cleaning or blasting weldments recei

46、ved in a rusted condition or in a condition tending to promote rusting, 3.23 Identification marking. Weldments covered by this specification shall be legibly and permanently marked in accordance with MIL-STD-130 and the applicable drawings. In addition, weldments shall be further identified and mark

47、ed as specified in 3.23.1 and 3.23,2. Weldments shall not be marked by identification stamp, welders stamp, or other marking in any area where the impression could act as a stress raiser leading to ultimate failure of the weld- ment. 3.23.1 Serial numbers. Weldments required to be indented with the

48、identi- fication marking in accordance with 3.23 also shall be indented with a serial number in characters of the same size as those of the identification mark. The serial number so assigned shall be selected, in regular sequence, from a block of serial numbers furnished by the contractor or procuri

49、ng activity. No two serial numbers shall be alike for the same part number, and all inspection records, reports, and correspondence shall thereafter refer to a specific weld- ment by its serial number. 3.23.2 Weldment drawing numbers. Where practicable, the applicable weld- ment drawing (not the finish machine drawing) piece number and revision letter shall be painted in relatively large cha