Analyze the process of forging quality need to know

Forging quality problems may occur in forging production, reaction in the process of heat treatment, machining or in use process, it may be due to the negligence of a production process caused by improper or technology, may also be caused by improper design and material selection, sometimes may be due to improper use and maintenance. For use in the process of mechanical parts made of forging defects and damage resulting from, in addition to the need to find out if the forging itself quality problems cause, also need to understand the use of parts stress conditions, place of work and the environment and use proper maintenance, etc. , only in ruled out the component design, material selection, heat treatment, mechanical processing and use factor, to concentrate on looking for from the forging itself quality defects and the causes of damage. Forging defects forming reason is various, according to the defects of macro and micro characteristics can be concluded that first impression, the defect is forging process factors related to raw material quality, is a set of process planning is not reasonable or improper execution process, the exact conclusion only after a detailed experiment analysis. About forging defects: ___________ some performance in terms of forging appearance: such as external crack, folding, crease, underfill, or lack of meat, pit, rough surface, or orange peel, etc. ; 2. Some performance within forgings, such as a variety of macrostructure defect, such as crack, hairline, osteoporosis, coarse grain, surface decarburization, non-metallic inclusions and different metal inclusions, white spots, segregation, dendritic crystal, residual, streamline shrinkage tube disorders, non-ferrous metal, and coarse grain ring, oxide film, etc. ; 3. Some are reflected in microstructure, such as precipitation of the second phase, etc. ; 4. Some forgings quality problems reflected in forging performance: such as room temperature strength and plasticity, toughness, fatigue performance is unqualified, the instantaneous strength, rupture strength and durable plastic, high temperature creep strength and other properties, or cold heat fatigue performance does not meet the use requirement. ⒌ regardless of the performance on the outside of the forgings, or the quality problem of the performance and performance within forgings: in most case, it is a mutual influence between them, are often interrelated, associated with, and a vicious cycle. Excessive heat or burn for example, are usually caused by coarse grains, forging crack, surface decarburization and plasticity, toughness and other mechanical properties reduced defects such as; Material internal inclusions may cause internal crack, crack in further expanding and development might be exposed to forging surface crack. So, in the analysis of forging quality, must be careful to observe and analyze the defect types and characteristics of 'grasp and study all aspects of it, all the links and' medium ', so as to find out the real reason why the quality problem. The general process of forging analysis is: survey the original situation; Find out quality problems; Experimental study on the analysis; Solving measures are put forward. Survey of (1) original situation: the original situation should include two aspects of raw materials situation and forging process. In terms of raw materials, to clarify forging type and chemical composition of materials, material specifications and raw materials quality assurance of experiments is shown on the single result, when necessary to make clear the smelting of raw materials, processing technology; In terms of forging process, in the investigation procedure formulation is reasonable, heating equipment and heating process is normal, after forging operations and forging forgings cooled and prepare proper heat treatment, etc. 2 find out quality problems: at this stage, the main find out forging defects, defect of macroscopic characteristics, and is identified as the raw material quality problem caused by defects or defects caused by forging process itself. (3) experimental research analysis: this is the main test phase, to identify the cause of the forging defects of defective forgings sampling analysis, determine its macro and microstructure characteristic, when necessary, also a comparison experiment of process parameter to study and analyze the causes of the forging defects. (4) solving measures are put forward: on the basis of clear forging defects reasons, combined with the actual production put forward the prevention measures and solutions, and verified by production practice, constantly sum up experience, to prevent the purpose of forging defects and improve the quality of forgings.