Detail of GB/T 34883-2017

Introduction of GB/T 34883-2017

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard was proposed by and is under the jurisdiction of National Technical Committee 75 on Heat Treatment of Standardization Administration of China (SAC/TC 75). Ion nitriding 1 Scope This standard specifies the terms and definitions, classification and designation, equipment and process materials, prepared nitriding parts, nitriding treatment, quality inspection of nitrided parts, safety and health requirements, energy consumption and environmental protection requirements and product report regarding ion nitriding of parts. This standard is applicable to the ion nitriding treatment of iron and steel parts, and may be referenced for the ion nitriding of other materials. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 536 Liquefied anhydrous ammonia GB/T 1220 Stainless steel bars GB/T 1221 Heat-resistant steel bars GB/T 1299 Tool and mould steels GB/T 1348 Spheroidal graphite iron castings GB/T 3077 Alloy structure steels GB/T 3634.2 Hydrogen - Part 2: Pure hydrogen, high pure hydrogen and ultra-pure hydrogen GB/T 4340.1 Metallic materials - Vickers hardness test - Part 1: Test method GB/T 7232 Terminology of metal heat treatment GB/T 8121 The terminology of technological materials for heat treatment GB/T 8979 Pure nitrogen and high purity nitrogen and ultra pure nitrogen GB/T 9451 Determination of total or effective thickness of thin surface hardened layers of steel parts GB/T 9452 Testing method for working zone of heat treatment furnace GB/T 9943 High-speed tool steels GB/T 10066.1 Test methods for electroheat installations - Part 1: General GB/T 11354 Determination of nitrided case depth and metallographic microstructure examination for steel and iron parts GB/T 12603 Classifications and designations for metal heat treatment GB/T 13324 Terminology of heat treatment equipment GB 15735 Requirements for the safety and health in production process of metal heat treatment GB/T 17358 Power consumption, measurement, and testing in heat treating production GB/T 17394.1 Metallic materials - Leeb hardness test - Part 1: Test method GB/T 18449.1 Metallic materials - Knoop hardness test - Part 1: Test method GB/T 19944 Fuel consumption calculation and measurement method in heat treating production GB/T 21736 Technical specifications of energy-saving combustion devices for heat treating GB/T 30822 Environment protection technical requirement for heat treatment JB/T 6050 Generalization of hardness test for heat treated iron and steel parts 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 7232, GB/T 8121, GB/T 13324 and the following apply. 3.1 prepared nitriding parts parts ready for ion nitriding treatment after proper conditioning treatment and machining 3.2 nitrided parts parts after ion nitriding 3.3 auxiliary cathode (anode) iron and steel components added on the cathode (anode) to improve the temperature uniformity of nitrided parts 3.4 conductance ratio of conducting time to pulse period in a pulse period 4 Process classification and designation The classification and designation of ion nitriding process shall meet the requirements of GB/T 12603, and the classification designation of ion nitriding process is 533-08. 5 Ion nitriding equipment and materials 5.1 Main technical parameters of equipment Main parameters of ion nitriding equipment are as follows: ——Power supply voltage, V; ——Number of phases of power supply; ——Supply frequency, Hz; ——Rated power, kW; ——Adjustable range of output voltage, V; ——Rated current output, A; ——Rated power of auxiliary heating power supply, kW; ——Frequency of pulse power supply, Hz; ——Adjustable range of conductance of pulse power supply; ——Maximum payload, kg; ——Rated temperature, ℃; ——Effective workspace size, mm; ——Ultimate pressure, Pa; ——Pressure rising rate, Pa/h; ——Consumption of cooling water, m3/h; ——Boundary dimension of furnace body, mm; ——Weight of furnace body, kg. 5.2 Technical requirements for equipment 5.2.1 High-frequency inverter pulse power supply and low-frequency chopper pulse power supply are adopted for ion nitriding generally. 5.2.2 The power supply shall have a reliable arc-control device. 5.2.3 The output voltage shall be continuously adjustable, without step if it is above 200 V. 5.2.4 The control system shall be provided with measuring and indicating instruments for voltage, current, temperature, pressure and flow, of which, those of temperature, pressure and flow shall have control and recording functions; 5.2.5 An inspection window shall be set in the body of ion-nitriding furnaces with water-cooled wall to observe the treatment of the parts inside. 5.2.6 At least two layers of heat shields shall be provided in the body of ion-nitriding furnaces with water-cooled wall. 5.2.7 Cooling water system shall be equipped with water shortage and overtemperature protection devices. 5.2.8 A circulating fan may be installed in the furnace body to improve the cooling speed of nitrided parts and shorten the process cycle. 5.2.9 The air supply system shall be equipped with devices that can control and stabilize the incoming gas pressure and flow. If ammonia gas is used as nitriding medium, a gas source drying (or purification) device shall also be set. 5.2.10 Under atmospheric pressure, the insulation resistance between cathode and anode of furnace body shall be measured with a 1,000V megger, and it shall not be less than 4 MΩ. Before measuring the insulation resistance between the cathode and anode of the furnace body, the cathode and anode connecting wires between the control cabinet and the furnace body shall be disconnected first to avoid damaging the components in the control cabinet. 5.2.11 The ultimate pressure of furnace body shall be less than or equal to 6.7 Pa. 5.2.12 In the no-load cold state, the time required to vacuumize to 6.7 Pa from atmospheric pressure shall be no more than 30 min. For equipment with vacuum system volume greater than 4 m3, such requirement may be appropriately eased. 5.2.13 The pressure rising rate of furnace body shall be less than or equal to 7.8 Pa/h, and shall be tested with the method specified in GB/T 10066.1. 5.2.14 The rated temperature of ion-nitriding furnaces shall not be lower than 650℃. 5.2.15 As for ion-nitriding furnaces only equipped with glow discharge power supply, the test of furnace temperature uniformity may be omitted, and the temperature uniformity of parts mainly depends on the charging mode and technological operations. 5.2.16 For ion-nitriding furnaces with auxiliary heating installation, if only auxiliary heating is used, the temperature of their working zone shall be determined with the method specified in GB/T 9452, and the furnace temperature uniformity shall not exceed ±10℃.

Contents of GB/T 34883-2017

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Process classification and designation 5 Ion nitriding equipment and materials 6 Prepared nitriding parts 7 Nitriding treatment 8 Quality inspection of nitrided parts 9 Safety and health requirements 10 Requirements for energy consumption and environmental protection 11 Product report Annex A (Informative) Effect of gas composition on nitrided case type and compound layer formation during ion nitriding Annex B (Informative) Key points for furnace charging Annex C (Informative) Test method for compound layer and nitride type in the compound layer