Mechanical Industry Standard of the People's Republic of China JB/T 7350-1994 Axial Flow Turbine Stainless Steel Blade Castings Published on 1994-07-18 Ministry of Machinery Industry of the People's Republic of China Implemented on 1995-07-01 Mechanical Industry Standard of the People's Republic of China Axial Flow Turbine Stainless Steel Blade Castings 1 Subject Content and Scope of Application JB/T7350-1994 This standard specifies the ordering, manufacturing, product dimensions, test methods, inspection, and acceptance rules for axial flow turbine stainless steel blade castings. This standard applies to all kinds of integrally cast stainless steel axial flow turbine blades and is the basis for the supplier to deliver products after rough processing and rough grinding of castings. Cited standards GB2106 GB6397 GB7233 GB9443 GB9444 GB11352 3Ordering requirements Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products Chemical analysis methods for steel and alloys Metal tensile test method Metal Charpy (U-notch) impact test method Metal Brinell hardness test method Metal Charpy (V-notch) impact test method Metal tensile test specimen Ultrasonic flaw detection and quality rating standard for steel castings Penetrant flaw detection and defect display trace rating method for steel castings Magnetic particle flaw detection and quality rating method for steel castings Carbon steel castings for general engineering 3.1 The purchaser shall specify the adopted standards, casting grades, material grades, corresponding technical requirements and inspection items and other additional instructions in the order contract and order agreement. 3.2 When placing an order, the purchaser must provide the supplier with the order drawing and indicate the product size, tolerance, surface roughness and test block position and size. 4 Technical requirements 4.1 Manufacturing 4.1.1 Smelting The steel for blades shall be smelted in an electric arc furnace or a refining furnace. With the consent of the purchaser, other smelting methods may also be used. 4.1.2 Casting Internal cooling iron is not allowed when casting blades, and the process increase should be removed before the final heat treatment. 4.1.3 Heat treatment Castings should be heat treated, and the final heat treatment should be normalizing and tempering. 4.1.4 Welding repair Approved by the Ministry of Machinery Industry on July 18, 1994 Implementation on July 1, 1995 JB/T73501994 4.1.4.1 The welding repair of casting defects should be carried out by qualified operators according to the welding repair process requirements before the final heat treatment of the casting, and the welding rod should be similar to the material of the casting. 4.1.4.2 Casting defects with a depth exceeding 25mm or exceeding 20% of the wall thickness, or a single defect area exceeding 6500mm2, shall be considered as major defects. Weld repairs of major defects shall be recorded and provided to the purchaser. 4.1.4.3 Before welding repairs, the defects shall be cleaned and inspected by magnetic powder or penetration methods to confirm that the defects are completely cleaned. 4.1.4.4 After welding repairs of major defects, stress relief heat treatment shall be carried out, and inspection shall be carried out according to the original flaw detection standards to confirm that the welding repair quality is qualified. 4.1.5 Mechanical processing 4.1.5.1 Castings shall be rough machined or ground at the supplier. 4.1.5.2 The finishing and grinding allowance of castings shall be agreed upon by the supplier and the purchaser. 4.2 Chemical composition The chemical composition shall comply with the provisions of Table 1. When the purchaser has no requirements, the residual elements in the steel shall not be used as the basis for acceptance. 4.3 Mechanical properties The mechanical properties of castings shall comply with the provisions of Table 2. The hardness HBS value shall not be used as the basis for acceptance if the purchaser has no special requirements. Table 1 ZG06Cr13Ni4Mo ZG06Cr13Ni5Mo ZG06Ci13Ni6Mo Note: Cu, W, V are residual elements. Material grade ZG06Cr13Ni4Mo ZG06Cr13Ni5Mo ZG06Cr13Ni6Mo Chemical composition Table 2 Mechanical properties Note: The purchaser can choose one of the V-shaped and U-shaped notches of the impact test specimen. 4.4 Casting quality General requirements The casting surface should be cleaned and there should be no defects such as sand holes, pores, cracks, etc. 4.4.2 Surface quality The surface roughness of the casting shall meet the requirements of flaw detection. 4.4.3 Tolerance of shape and size Akv (Aku) >50 (≥63) 221-286 JB/T7350-1994 4.4.3.1 The shape and size of the casting shall meet the requirements of the order drawing and agreement. 4.4.3.2 The shape of the blade shall meet the requirements of the sample. When measuring with a three-dimensional sample, the gap between the profile and the sample shall not exceed 0.002D (D is the nominal diameter of the runner). See Figure A1 in Appendix A (Supplement). 4.4.3.3 The blade thickness deviation is (-0.04~+0.08)T+2mm (T is the drawing thickness at the measuring point). The location and number of measuring points shall be agreed upon by the supply and demand parties. 4.4.3.4 The waviness of the front and back sides of the blades is expressed by the H/L value (L is the gap length, H is the maximum gap size within this length), see Figure A2 in Appendix A. The H/L value should be less than 2%. The waviness of the back side that is prone to cavitation should be less than 1%. 4.4.3.5 The maximum allowable gap between the sample and the blade within 50mm of the front and back sides of the water inlet head is 1.5mm; the allowable deviation of the front and back sides of the remaining parts is 0.0005D. 4.4.3.6 When the diameter of the runner is less than or equal to 3660mm, the edge thickness deviation of the water outlet is -0.Tmm; when the diameter of the runner is greater than 3660mm, the edge thickness deviation of the water outlet is -mm, and the allowable deviation of the front and back profile is 2mm. 4.4.4 Non-destructive testing Castings should be subjected to ultrasonic and magnetic particle testing or dye penetrant testing. The inspection location and acceptance level shall be agreed upon by both parties. 5. Test methods and inspection rules 5.1 Chemical composition analysis The sampling and analysis methods of chemical composition analysis shall comply with the provisions of GB222 and GB223. 5.2 Mechanical properties test 5.2.1 Test specimen 5.2.1.1 The shape and size of the test specimen for mechanical properties test shall comply with the provisions of GB6397. 5.2.1.2 The test block shall be cast separately or attached to the casting body as agreed upon by both parties, and heat treated together with the casting. The number of test blocks must be sufficient. The shape and size of the single-cast test block shall comply with the provisions of GB11352, and the thickness of the attached cast test block shall not be less than 28mm. 5.2.1.3 Take 1 tensile test specimen and 3 impact test specimens from the same batch of test blocks. If the test specimen is defective, it shall be scrapped and re-sampled from the same batch of test blocks. 5.2.2 Tensile test Tensile test shall be carried out in accordance with the provisions of GB229 or GB6397. 5.2.3 Impact test Impact test shall be carried out in accordance with the provisions of GB229 or GB2106. The average value of the three specimens shall meet the requirements of Table 2. It is allowed that the impact value of one specimen is lower than the value specified in Table 2, but it shall not be lower than 2/3 of the specified value. 5.2.4 Hardness test shall be carried out in accordance with the provisions of GB231. 5.2.5 Retest and reheat treatment When the mechanical properties test results are unqualified, double sampling shall be carried out for retest. If it is still unqualified, the supplier can reheat treat the casting and the test block together, and then retest. The test results shall be qualified only if they meet the requirements of this standard. The number of reheat treatments shall not exceed two times. 5.3 Casting shape and size inspection Casting shape and size inspection shall be carried out in accordance with the provisions of Appendix A. 5.4 Nondestructive testing 5.4.1 Surface inspection JB/T73501994 The magnetic particle inspection of the casting surface shall be carried out in accordance with the provisions of GB9444. The penetration inspection shall be carried out in accordance with the provisions of GB9443. Ultrasonic inspection Ultrasonic inspection of castings shall be carried out in accordance with the provisions of GB7233. 6 Quality certificate At the time of delivery, the supplier must provide the purchaser with a quality certificate, which shall include the following contents: a. Order contract number; b. Order drawing number; c. Product material brand; d. Standard number; Smelting furnace number, part number; f. Product size and weight; g. Chemical composition analysis results; h. Mechanical properties test results; i. Nondestructive test results; j. Blade profile inspection records; k. Major defect welding repair records; 1.Other additional inspection results. Marking, packaging The supplier shall mark each blade casting with the contract number, furnace number, part number, etc. and circle them with white paint. 7.1 The supplier shall pack according to the transportation conditions. 4 Appearance inspection JB/T7350-1994 Appendix A Shape and size inspection of blade castings (Supplement) The blade shape shall be inspected using the three-dimensional sample shown in Figure A1. The sample and instructions for use shall be provided by the purchaser. Inlet side Surface waviness inspection Figure A1 Stereoscopic sample Outlet side A2.1 The waviness is generally inspected with a 1m long flexible ruler parallel to the water flow direction (tangential) and perpendicular to the water flow direction (radial), as shown in Figure A2. A2.2 During the inspection, stick the flexible ruler on the blade surface so that the surface of the ruler conforms to the smooth curved surface of the blade. When measuring one surface and then the adjacent surface, the overlap between the flat ruler and the previous curved surface shall not be less than 150mm. If the length of the flat ruler used is shorter than 650mm due to site constraints, the overlap between the front and rear parts should be greater than 10% of the ruler length during the inspection. S Vertical direction of water flow JB/T7350-1994 Figure A2 Waviness inspection A3 Inspection of water inlet head line and water outlet line Blade surface A3.1 The water inlet head line is inspected with the sample shown in Figure A3. When the three-dimensional sample shown in Figure A1 is used to inspect the blade shape, the water inlet sample is configured according to the section to be measured. A3.2 The water outlet line is inspected with the sample shown in Figure A3. The number of samples is determined by the purchaser. Water outlet -10%T (designed) 50 Water outlet line inspection sample Additional instructions: JB/T7350-1994 This standard is proposed and managed by the Deyang Large Castings and Forgings Research Institute of the Ministry of Machinery Industry. This standard was drafted by Qiqihar Casting, Forging and Welding Research Institute. The main drafters of this standard are Feng Baoquan and Ma Qingsheng. 7 People's Republic of China Mechanical Industry Standard Axial Flow Turbine Stainless Steel Blade Castings JB/T73501994 Published and issued by the Mechanical Science Research InstitutebZxz.net Printed by the Mechanical Science Research Institute (No. 2 Shouti South Road, Beijing Format 880×1230 Postal Code 100044) 1/16 Printing Sheet 3/4 Word Count 12.000 First Edition in January 1995 First Printing in January 1995 Print Quantity 1-500 Price 6.00 Yuan Mechanical Industry Standard Service Network: http://www.JB.ac.cn661_0 Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.