Fabricantes de pulvimetalurgia --
El concepto y el principio del procesamiento pulvimetalúrgico a base de hierro.
This article mainly focuses on the standard of USA powder metallurgy MPIF-35.
Code representation method for powder metallurgy materials
In the case of powder metallurgy structural parts, the method and designation of powder metallurgy material codes are specified based on chemical composition and the minimum strength expressed in 10 cubic psi. For example, FC-0208-60 is a powder metallurgy copper steel material with a nominal composition of 2% Cu and 0.8% combined carbon, and a minimum yield strength of 60 in the sintered state × 10 cubic psi (410MPa).
The code system provides a convenient method for indicating the chemical composition and minimum strength value of any standard powder metallurgy material. This code system is based on an established system in industry, and uses an additional 2 or 3 digit suffix to represent the minimum strength in place of the density range suffix letter. For each standard material, density is given as a standard value.
Prefix letter code
A represents aluminum; C represents copper; CT represents bronze; CNZ stands for zinc white copper; CZ represents brass; F represents iron; FC represents iron copper or copper steel; FD represents diffusion alloy steel; FF represents a soft magnet; FL represents pre alloyed iron-based materials (excluding stainless steel); FN represents iron nickel or nickel steel; FS represents silicon steel; FX represents copper infiltration into iron or steel; FY represents iron and phosphorus; G represents free graphite; M represents manganese; N represents nickel; P represents lead; S represents silicon; SS represents stainless steel (pre alloyed); U represents sulfur; Y represents phosphorus; Z represents zinc.
Powder metallurgy heat treatment
For iron-based powder metallurgy parts with a combined carbon content of ≥ 0.3%, quenching hardening and tempering can be carried out to improve strength, hardness, and wear resistance. The effective combination of carbon and other alloying elements in materials and the material density determine the degree of hardenability under any given quenching conditions. The micro indentation hardness value obtained by quenching and hardening is 650HK100g (56HRC) and higher.
For the heat treatment and/or carburization process of iron-based powder metallurgy parts, it is recommended to perform it in a protective atmosphere gas or vacuum. Salt bath is not recommended as it may cause surface absorption of salt and subsequent salt leakage, as well as internal corrosion of the material. When low-density parts are carburized, infiltration may occur, while parts with higher density (7.0g/cm3 or higher) may form a carburized layer during carburization. In order to ensure the specified carbon content is achieved, it is necessary to control the carburizing process.
In order to achieve higher temperature and durability, tempering or stress relief is required after quenching; Usually, it is tempered at a temperature of 1 inch (25.4mm) based on the thickness of the cross-section for 1 hour. Given that obtaining the tempering temperature for surface hardness may not necessarily result in optimal strength performance, a comprehensive consideration must be given between hardness and properties such as impact energy. Among the factors that determine the final hardness, tempering temperature is a major factor.
GOLDBAT GROUP is a technology-based manufacturing enterprise specializing in the production and manufacturing of iron-based powder metallurgy components. The factory covers an area of 13333.40 square meters and has a complete set of powder metallurgy pressing, sintering, post-processing, and surface treatment production lines. The quality control of the product production process is scientifically guaranteed and tested, and has passed the IATF16949-2016 automotive industry quality system certification.
