--> Buy True-PDF --> Auto-delivered in 0~10 minutes. TB/T Translated English of Chinese Standard: TB/T

Transcription

1 Translated English of Chinese Standard: RAILWAY INDUSTRY STANDARD TB OF THE PEOPLE S REPUBLIC OF CHINA Technical Specification for Solid Rolled Steel Wheel for Rolling Stock 铁道车辆用辗钢整体车轮技术条件 Issued on: July 10, 1997 Implemented on: January 1, 1998 Issued by: Ministry of Railways of the People's Republic of China Page 1 of 39

2 Table of Contents Forward Scope Normative References Type Size of Wheel Technical Requirements Test Methods Inspection Rules Package, marking, and Quality Certificate Warranty Appendix A (Standard s Appendix) Shot Peening Strengthening of Wheel Page 2 of 39

3 Forward This Standard was prepared on the basis of equivalently adopting UIC812-3 Technical Specification for the Supply of Non-Alloy Steel Solid Rolled Steel Wheel for Railway Locomotive; some provisions of national and other standards are supplemented for adapting the national situation. This Standard was proposed by the Ministry of Railway Science and Technology Development Department. This Standard shall be under the jurisdiction of Standards and Metrology Research Institute of the Ministry of Railway. Drafting organizations of this Standard: Standards and Metrology Research Institute of the Ministry of Railway, Metals and Chemistry Research Institute, China Academy of Railway, and Sifang Rolling Stock Research Institute of the Ministry of Railway. Chief drafting staffs of this Standard: Han Ying, Zhang Yingzhi, Zheng Weisheng, Liu Xinming, and Zhang Bin. Page 3 of 39

4 Technical Specification for Solid Rolled Steel Wheel for Rolling Stock 1 Scope This Standard specifies the type size and geometric tolerance, technical requirements, test methods, inspection rules, package, marking and quality certificate and etc. of solid rolled steel wheel (hereinafter refers to wheel) for quasi rail vehicle. This Standard is applicable to the manufacturing, ordering, and testing of solid rolled steel wheel for rolling stock with passenger train speed 160km/h, and freight train speed 120km/h. 2 Normative References The following normative documents contain provisions which, through reference in this Standard, constitute provisions of this Standard. At the time of publication, the editions indicated were valid. All the standards will be revised and all parties who reach an agreement according to this Standard are encouraged to study whether the latest editions of the following standards are applicable. GB Method of Sampling Steel for Determination of Chemical Composition and Permissible Variations for Product Analysis GB 223 Methods for Chemical Analysis of Iron, Steel and Alloy GB Test Method for Macrostructure and Defect of Steel by Etching GB Method of Tensile Tests for Metal GB/T Metallic Materials-Charpy Notch (U-Shaped Notch) Impact Test GB Test Method for Brinell Hardness of Metal GB Solid Rolled Steel Wheel for Railway GB Microscopic Testing Method for the Non - Metallic Inclusions in Steel TB Wheel Profile for Locomotive and Car ZBY Commonly Used Specification for A-Mode Ultrasonic Flaw Detector Page 4 of 39

5 4.1.3 Allowable tolerances (%) of chemical composition analysis and melting analysis of finished wheel are shown as follows: 4.2 Wheel manufacture Steel making C: or P: Si: or S: Mn: or Wheel steel shall be manufactured by excellent-quality killed steel molten in electric furnace, open hearth, or revolving furnace; if it is agreed by the buyer and seller, other melting method can also be adopted, and go through the refining treatment outside of the furnace, the hydrogen content in the molten steel is 3.5ppm. Steel ingots must be casted from the bottom. After stripping, the steel ingots must conduct fully slow-cooling in the slow-cooling pit. When it undertakes vacuum degassing treatment, it can realize stack-cooling directly Wheel thermoforming Wheel shall be manufactured by the steel ingots with head-cutting, and the headcutting amount shall be sufficient to eliminate the harmful part that may influence the wheel quality on two sides of the steel ingots, all surfaces of the steel ingots must not have any defects that may influence the rolling quality. During the thermoforming heating period, the over-burning and over-heating of wheel steel billet shall be avoided, thermoforming heating temperature shall not exceed 1250, and the thermal machining final temperature shall be controlled within the range of 850 ~1000. After the thermoforming of wheel manufactured by steel that doesn t carry out vacuum degassing treatment, measures to eliminate white spots must be taken, such as isothermal, slow cooling, and etc Wheel s identification marking during the manufacturing process All steel ingots, steel billets, cutting bars, and wheels must be marked clearly on each process, so that each wheel can be identified before delivery. If such mark is different from the final mark of the finished wheel, then such mark shall be as shallow as possible, even leaves no trace on the finished wheel Wheel heat treatment Wheel rim shall be carried out quenched and tempered treatment, water shall be prevented to enter into the spoke during the quenching period. Page 8 of 39

6 No more than Grade-2 general looseness, center looseness, segregation, and nonmetallic inclusion are allowed to exist. 4.5 Non-metallic inclusion In the three specimens of rim, the grade of each inclusion shall conform to the following requirements: Class B (alumina inclusion) shall be no more than Grade 1; Class A (sulphide inclusion), Class C (silicate inclusion), and Class D (globular oxide) shall be no more than Grade 3 respectively. 4.6 Ultrasonic flaw detection All wheels, after the heat treatment and mechanical machining, shall be carried out ultrasonic flaw detection one by one. To detect the internal discontinuity of all wheels rims, adopt the following specified equipment to conduct ultrasonic flaw detection as per the following procedures Flaw detection equipment shall conform to the provisions of ZB Y , and its frequency band shall meet the requirements of flaw detection method Probe operating frequency: 2.25~5MHz Probe structure and dimension shall be applicable to all testing methods Ultrasonic flaw detector shall be equipped with defect automatic alarm system Proper couplant shall be used between the testing surface and the probe, however, the impermissible corrosion shall not be generated on the rim. The same couplant shall be used for the adjusting instrument, calibrating instrument, and in the testing period One wheel or one segment of rim, which has artificial simulation defect shall be used as comparison test block to calibrate the instrument. Instrument sensitivity shall be adjusted to make the artificial defects specified in Clause 4.6.7, Clause 4.6.8, and Clause generate 1/2 full magnitude of the reflected echo During the axial test period, the artificial defect shall be placed at half thickness of rim, the diameter perpendicular to rim side face is about 3.2mm, and the depth of flat-bottom hole is about 25~38mm (see Figure 2). Page 10 of 39

7 formal table for future checking Lighting illumination shall be checked once a week, the test results shall be recorded in the specified table for future checking During magnetic particle testing period, the test surface of wheel shall be maintained clean Wheel s test surface shall, under the condition of fully covering the detection medium, adopt continuous magnetizing method to detect the discontinuous defect on any axis Such checking shall be performed after the final mechanical machining Discontinuous defect detected by magnetic particle testing shall be eliminated through mechanical machining or grinding methods, the dimension of wheel through trimming shall meet the minimum dimension requirements specified in the drawing, if the wheel is evaluated to be qualified through the repeat magnetic particle testing, it can be regarded as the qualified product, otherwise it shall be rejected. 4.8 Residual stress Sample one wheel from each batch, apply the cutting method to test the residual stress, after cutting the reduction value of the distance between two marks shall be less than 1mm, see Clause 5.5 for the test method. 4.9 Shot peening strengthening Each wheel s spoke shall be carried out shot peening strengthening treatment, in order to ensure the effect of shot peening strengthening, it shall be carried out after the wheel s ultrasonic testing, magnetic particle testing, and mechanical machining. Process requirements of shot peening strengthening: Steel shot applied in shot peening shall conform to the technical requirement of cast steel shot specified in Appendix A, its dimension shall be No.550 or larger hardening steel shot specified in Appendix A. Shot peening machine shall be equipped with a separator, which is used for continuously eliminating the broken steel shot, and add new ones at any time, so that ensure the proportion of No.550 or larger steel shots in the shot peening machine is no less than 85%. Shot peening strength shall be sufficient, on the designed wheel closer inside and outside face of spoke on hub arc and inside arc face of rim, to generate average arc height of Almen C-2 test piece no less than (0.191+)m. Shot peening area shall be inside and outside face of wheel spoke, extending to Page 13 of 39

8 internal and external arc of rim, as well as the central point on the inside and outside face of hub. Arc height shall be measured as specified in Clause A.2 and Clause A.3 of Appendix A. To ensure the shot peening effect, the surface coverage shall be 100%, i.e. reaching complete covering of Almen C-2 test piece. The minimum shot peening time shall be sufficient to ensure the shot peening surface to reach the complete covering of Almen C-2. Before shot peening, the spoke surface can perform necessary surface treatment, however, the treatment result shall not lead to rejection. In addition to key arc positions (hub arc on the inside and outside face of spoke, and inside arc of rim), portable shot peening machine can be used to re-shot-peening against the spoke area (area is no more than 50mm X 75mm) that needs re-trimming. The portable shot peening machine can perform shot peening against Almen C test piece, and can generate average arc height no less than 0.203mm within proper time. Such equipment shall be test once on the Almen C test piece after each shift (8h), and the test results shall be stored. After shot peening, the appearance of rim and hub shall not be rejected. The number of measurement against arc height shall be fully ensured to meet the regulatory requirements. If in a test, the requirement of Almen C-2 s arc height of 0.203mm isn t met, then twice re-inspection can be performed; combine the twice re-inspection results and the first result and find out the average value, which shall not be less than 0.203mm, and the number of the above three values less than shall not exceed one. If the test value can t meet such condition, take corrective measures, and obtain qualified test value before the productive shot peening process. If the average arc height of disqualified test result is 0.152mm or 0.178mm, then from the previous qualified test to the disqualified test period, after shot peening, half of the wheels shall be re-shotpeening, while the shot peening time shall be half of the standard (normal) peening time at least. If the arc height is less than 0.152mm, then all shot peening wheels after the previous qualified test shall be re-shot-peening, while the shot peening time shall be the standard (normal) peening time Static balance After mechanical machining, the passenger train wheel can be carried out static balance test one by one, while the freight train wheel doesn t need carry out static balance except the users special requirements. Page 14 of 39

9 11 Ultrasonic flaw detection Each batch One by one Rim 12 Magnetic particle testing Each batch One by one Spoke 13 Residual magnetic inspection Each batch One by one Entire wheel 14 Overall dimension Each batch One by one Entire wheel, and mark the wheel diameter size 15 Surface quality Each batch One by one Wheel surface 16 Static balance Each batch One by one Passenger train wheel 6.4 Re-inspection rules Macrostructure: if the white spot, shrinkage cavity residual, delamination, crack, skull patch, abnormal-shape segregation and metallic foreign body are found in the macrostructure, then such batch of wheel shall be judged disqualified; if the macrostructure is disqualified due to other items, take two wheels from such batch to conduct re-inspection, as long as there is one disqualified, then such batch shall be judged disqualified Non-metallic inclusion: when the non-metallic inclusion is inspected disqualified, double specimens can be taken from the same batch of wheels to conduct the reinspection of non-metallic inclusion. As long as there is one disqualified re-inspection result, then such batch shall be judged disqualified If the rim tensile, hardness, spoke impact under room temperature, and metallurgical structure are tested to be disqualified, double specimens shall be taken from other wheels of the same batch to conduct re-inspection, as long as there is one disqualified re-inspection result, such batch of wheels is judged to be disqualified. Manufacturer can perform repeat heat treatment against such batch of wheels, however, the number of repeat heat treatment shall not exceed twice, and the number of tempering can be neglected. In addition to macrostructure, chemical composition, and non-metallic inclusion tests, the wheels that go through the repeat heat treatment shall perform the rest inspections and acceptances. 7 Package, marking, and Quality Certificate 7.1 Package Wheel surface shall be completely coated with user specified or approved protective coatings, while the protective layer shall evenly cover the entire wheel surface In order to prevent the mechanical damages towards the wheel, especially the two ends of hub hole and flange, wheels shall be transported in the containers or its package mode shall be agreed by the buyer and the manufacturer. 7.2 Marking Page 20 of 39

10 Each wheel shall be printed with manufacture mark on the outside face of rim and internal end face of hub, the hot or cold printing modes can be adopted, however, the printing mode shall be approved by the buyer. Manufacture mark s font height shall be 9~15mm, while word mark depth shall be 1~2mm. When the manufacture mark is made on the outside face of the rim, the distance between the font lower baseline and rim inner diameter circumferential edge shall be 5~7mm; when the manufacture mark is made on the internal end face of hub, the distance between the font upper baseline and hub outer diameter circumferential edge shall be 5~7mm. The mark orders are arranged as follows, and see Figure 10. a) Last two digits of the manufacture year; b) Manufacture month; c) Plant mark; d) Wheel steel code; e) Wheel model; f) Melting furnace number; g) Wheel serial number; h) Inspector mark. The marking sequence must not be changed; the wheels without marking or with unclear marking shall not be delivered. Residual imbalance position and mark shall be performed as per the provisions of Clause Quality certificate Each batch of wheels shall be attached with the quality certificate issued by the manufacturer s Technical Supervision Department. The contents of quality certificate shall contain the following ones: a) Manufacturer name; b) Wheel specification and model; c) Wheel steel code; d) Wheel quantity; e) Melting furnace number; Page 21 of 39

11 Appendix A (Standard s Appendix) Shot Peening Strengthening of Wheel A1 Technical specification of cast steel shot A1.1 This technical specification equivalently adopts SAE recommended SAE J827 MAR 90 Technical Specification of Cast Steel Shot. A1.2 Application scope This technical specification specifies the chemical composition, hardness, metallurgical structure, physical property, and other technical requirements of cast steel shot applied in hardening of shot peening (hereinafter refers to cast steel shot). A1.3 Reference documents A1.3.1 SAE J444 Shot Peening Hardening and Surface Eliminating Applied Cast Steel Shot and Particle Size A1.3.2 SAE J445 Metal Test of Metal Shot and Particle A1.3.3 ASTM E384 A1.3.4 ASTM E370 A1.4 Manufacture of caste steel shot Cast steel shot used for shot peening hardening shall, on the premise of controlling dimension, be generated by molten steel spray method and rapid cooling method; the generated particles shall perform heat treatment, and screen in the dimension range from S70 to S1320 or larger specified in the provision of SAE J444. A1.5 Classification Cast steel shot shall be classified as per the classification method specified in SAE J444, three digits following S indicates its nominal size, namely, a multiple of one tenthousands against per 25.4mm (per inch); for instance, S-330, namely, indicates the cast steel shot with nominal screen mesh mm (0.0331inch). A1.6 Chemical composition Finished cast steel shot shall conform to the chemical composition listed in Table A1. Page 24 of 39

12 or more than 20% particle diameter. e) Metallurgical structure There shall not be carbide net, local decarburization, crystal grain boundary separation, or high-temperature transformation product (i.e. pearlite). The amount of particles with these defects shall not exceed 15% tested particles. f) Non-magnetic material Calculate as per weight, non-magnetic material shall not exceed 1% steel shot sample. A1.10 Specific gravity Specific gravity of cast steel shot shall be no less than 7g/cm 3. A1.11 Mechanical test Consistency inspection method of delivered steel shot and determination of fatigue life of different-model steel shot can refer to SAE J445 Metal Test of Metal Shot and Particle. A1.12 Inspection method a) Sampling Specimen used for chemical analysis, hardness, metallurgical structure, specific gravity, bad defect, and mechanical tests must be carefully taken from each delivery or production batch, and shall be representative. b) Embedding of test sample Sample used for hardness, metallurgical structure, bad defect tests shall be embedded into the embedded medium of Bakelite or other suitably strong metallurgical sample, about a layer deep. After embedding, the sample shall be ground to the particle center and polished, check it with metalloscope as per the specified method. c) Hardness test Hardness measurement shall be performed on the radius of ten particles in the embedded specimen. Hardness shall be determined as per ASTM E384, S280 particles shall use 500g load; while S330 or larger particles shall use 500g or 1000g load, other microhardness test methods, which use various machines calibrated by the known Page 26 of 39

13 standard and obtain reliable hardness conversion value, can also be adopted. Approximate conversion value of Rockwell Hardness C can be obtained from ASTM A370. d) Metallurgical structure After embedding and polishing, the specimen shall be etched by the metallurgical reagent, and inspect under 500x magnification. e) Bad defect Bad defect shall be measured by 10X magnification metalloscope, all particles in the embedding position shall be tested. f) Specific gravity Put 50mL of water into 100mL measuring cylinder, add 100g of steel shot, then record increasing volume value. 100g weight is divided by increasing volume value, and obtains specific value in unit of g/cm 3. The highly-required specific gravity measurement shall be performed by hydrometer method. g) Non-metallic material Use handheld magnet to separate magnetic steel shot from the non-metallic impurities, weigh the non-metallic impurities, and calculate the percentage in the original sample. A1.13 Size of cast steel shot Refer to Table A2 for the size of cast steel shot. Page 27 of 39

14 A2 Technical specification of test piece, fixator, and measuring tool A2.1 This technical specification equivalently cites Standard SAE J442 AUG79. A2.2 This technical specification equivalently cites SAE recommended SAE J443 Operation Procedure for Test Piece of Shot Peening Hardening supplemented by SAE J442 AUG79. A2.3 Overview of control method The operation of one shot peeing machine firstly indicates to control the shot flow features that make the workpiece to bear the shot peening hardening. The measurement basis of these features: when one end of the steel billet is sandwiched by the fixator, exposed to the shot flow to bear impact, the steel billet shall bend and arch against the table board of fixator, and demonstrate a convex surface at the peening shot side. The extent of curvature (degree of curvature) on the standard specimen shall be regarded as the measurement of the strength of shot flow; especially depends on the features of shot flow, test piece property, and original state exposed in the shot flow. The features of shot flow consist of steel shot s speed, size, shape, specific gravity, material type, hardness and other parameters. The state exposed in shot flow indicates the time period, impact angle and shot peening flow rate. The performance of test piece depends on the size and mechanical property of it. Basing on the above principle, SAE recommends the following standard test piece, fixator, and measuring tool. The technical requirement, use method, and standard name of these devices are listed in this Standard. A2.4 Technical requirements of hardness testing device A2.4.1 Test piece and fixator Refer to Figure A1 for the shape and size of N-type, A-type, and C-type standard test pieces. Refer to Figure A2 for the fixator of standard test piece. Refer to Figure A3 for the relationship among N-type, A-type, and C-type test pieces. These curves demonstrate the readings of N-type, A-type and C-type test pieces under the same shot flow and exposed features. A2.4.2 Measuring tool Refer to Figure 4 for the measuring tool to determine the curvature of test piece. The curvature of test piece shall be obtained from the height of horizontal and vertical arcs that cross the standard string, while arc height is measured through the displacement of right angle plane center point of rectangle formed by four balls on the non-shotpeening surface. When such measuring device is used, measuring tool s calibration bar top shall be on the non-shot-peening surface of test piece. Page 30 of 39

15 A3.3 Shot peening strength Shot peening strength is expressed by arc height of shot peening test piece. Its curvature value indicates time function of steel shot s mass, hardness, spraying angle and shot flow against the test piece. Strength mainly has the two utilization purposes: (a) Check the performance of shot peening machine including the treatment method of various components; (b) specified effect shall be reached on the components. Technical specification (e.g. 12A) of one strength means the arc height measured when the following saturated value is reached. The below mentioned effective coverage rate indicates the saturated index value in case the same steel shot is used. A3.4 Saturated value Saturated value can be obtained by shot peening time s corresponding arc height curve. Though shot peening against a series of test pieces, gradually increase the shot peening time, and keep other conditions unchanged, then make a curve with a series of shot peeing time s corresponding arc height. Refer to Figure A5 for the general shape of curve drawn by these test points. When pass the maximum curvature of the curve, to increase the arc height of test piece needs increase more and more shot peening time, such turning point is the obtained saturated value point. It can be observed from maximum curvature position, i.e. Point A in Figure 5, if the shot peening period is increased twice, then the arc height of point on the curve only increases x %. As for some applications, it is sufficient to increase the arc height by 20% when the shot peening time is increased twice. As for some crucial application occasions, take at 10% inflection point. If it is a little larger than 10%, longer shot peening time is required to reach the inflection point on the curve. In addition to the consistence between test piece exposing method and components key area exposing method in the fields of angle, speed, passing shot quantity per minute, the time required by shot peening a product component is different from the time require by saturating a test piece. If the component hardness is significantly different from test piece 44 to 50HRC, to make components reach saturation is also different. For instance, a hard cementite component requires longer time to reach 100% coverage; while a softer component requires shorter time than the test piece. After finding out the satisfactory-result operation condition on the components, saturated curve shall be used to control the repeatability of operation state. Page 32 of 39

16 Use the setting value of machine determining the arc height and steel shot size to prepare the production organization procedure, which is instructed as follows: a) Provide a fixator, make the fixed test piece, in the way, simulate the shot peening component surface that needs hardening maximum. If there are several surfaces like this, fixator shall provide fixing positions of the test pieces that need increasing. b) Firstly use the estimated machine setting values (steel shot type and size, shot flow, speed and impact angle) to place a batch of test pieces to the shot flow; record, after each different shot peening time, the curve that can be drawn as per Figure A5. c) If it is checked from the curve that the shot peening strengthening measurement value doesn t enter into the expected range, the machine setting value shall be changed; if larger arc height value is required to reach, when the steel shot type is determined, faster shot speed and larger particle diameter shall be used. If smaller arc height value is required to reach, lower shot speed and smaller particle diameter shall be used. Speed change can be realized through changing the flywheel speed and air pressure. Sometimes the shot flow direction can be adjusted, however, the most effective shot peening hardening treatment indicates the main shot flow vertically spray to the crucial segment of components that needs shot peening hardening treatment. d) After the new setting value is confirmed, arc height value shall use new test piece again to verify as per the Clause b) of this section. e) If the first test obtains Curve B in Figure A6, while the expected one is arc height of the horizontal dotted line, then it illustrates that both steel shot speed and size are too large, then one or both of the two ones shall be reduced. If the second test obtains Curve C, it illustrates either steel shot speed or size is too small. Repeat the test several times till Curve D in Figure A6 conforming to the arc height requirements are obtained. f) When machine setting finds the inflection point, the expected arc height, coverage rate, and shot peening time are also obtained. E.g. on Curve D in Figure A6, shot peening time T is corresponding to Point Q on the curve, which are the commonly used values. A typical terms used in the production s shot peening hardening technology is called shot peening hardening strength range, e.g. from 10A to 14A and 98% coverage rate mean the arc height measured on standard test piece A is from 10A to 14A, and 98% component surface area is covered by slight concave pit. Then product component shall go through the same shot peening hardening treatment procedure, and carry out shot peening hardening treatment as per the arc height value obtained from saturated curve and coverage equivalent time Page 34 of 39

17 inspected by visual observation. Since the shape and hardness of component are different from that of test piece, complete coverage required time reached on the component is different from saturation required time reached on test piece. Hard components need longer time, while soft components need shorter time. The optimal result is to use steel shots harder than components to conduct shot peening hardening treatment against the components. g) Determination of surface area coverage Surface area coverage rate of component or test piece can be obtained from the following one or several combined procedures: (1) Use 10x magnifier to inspect the surfaces of all (100%) filleted corner, cavity, groove and hole. When the surfaces with original clear boundaries are totally covered by overlapping pit, it illustrates that the original surface is completely covered. (2) Use sensitive fluorescent tracer to cover component, perform shot peening as per the shot peening time obtained from Clause f), then use ultra intensity violet light to explore the fluorescent tracer, if any continuous fluorescent tracer (tiny spots are allowed) are found on the surface, it illustrates that complete coverage requirements are not met. (3) Use dyeing ink to coat component, shot peening component as per the strength and shot peeing time obtained from Clause f), then use white light to visually observe whether there is residual dyeing ink, if any continuous dyeing ink (tiny spots are allowed) is found on the surface, it illustrates that complete coverage requirements are not met. (4) After the shot peening hardening treatment against a component, an obvious surface replica is formed. Such replica can compare with other replica with different coverage rate when projected onto a screen. (5) The same as to determine the arc height, test piece shall be polished or jetted in shot flow, and placed in the imaging field of metallurgical camera. Use transparent paper and magnifier with diameter 50mm, through polishing test piece and comparison, delineate the pit area and its inclined surface, use planimeter to measure the pit area. The ratio between pit area and total area is the coverage percentage. A3.8 Common process control Shot peening hardening process is the same as many other processes, the existing shot peening process can t make proper control through the non-destructive inspection of component shot peening, therefore, the process itself needs to be controlled to reach the consistence and reliable results. Determining the residual stress on the Page 35 of 39