Scope This SAE standard covers the minimum mechanical properties measured on separately cast test pieces of varying thickness and microstructural requirements for ductile iron castings used in automotive and allied industries. Castings may be specified in the as-cast or heat-treated condition. If castings are heattreated, prior approval from the customer is required. The appendix provides general information on chemical composition, microstructure and casting mechanical properties, as well as other information for particular service conditions. In this standard SI units are primary and in-lb units are derived. Unless otherwise indicated, the latest revision of SAE publications shall apply 2.
|Published (Last):||2 October 2010|
|PDF File Size:||10.75 Mb|
|ePub File Size:||17.74 Mb|
|Price:||Free* [*Free Regsitration Required]|
Scope This SAE standard covers the minimum mechanical properties measured on separately cast test pieces of varying thickness and microstructural requirements for ductile iron castings used in automotive and allied industries. Castings may be specified in the as-cast or heat-treated condition. If castings are heattreated, prior approval from the customer is required.
The appendix provides general information on chemical composition, microstructure and casting mechanical properties, as well as other information for particular service conditions. In this standard SI units are primary and in-lb units are derived. Unless otherwise indicated, the latest revision of SAE publications shall apply 2.
The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user. SAE invites your written comments and suggestions. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.
Grades The grades, mechanical properties and metallurgical description are shown in Table 1. Minimum properties are specified by agreement Between manufacturer and purchaser. It is desired that separately cast test bars reflect properties of the castings they represent. Casting process for separately cast test pieces shall be agreed upon between manufacturer and purchaser.
Hardness The hardness ranges shown in Table 1 are for guidelines only. The foundry shall exercise the necessary controls and inspection techniques to insure compliance with the typical hardness range.
Brinell hardness shall be determined according to ASTM E 10, Standard Test Method for Brinell Hardness of Metallic Materials, after sufficient material has been removed from the casting surface to insure representative hardness readings. The 10mm tungsten ball and kg load shall be used unless otherwise agreed upon.
Heat Treatment The heat treatment of castings and test specimens produced to this standard in order to meet hardness or other mechanical property requirements, for thermal stress relief or for other purposes is permissible only with the express approval of the casting purchaser. Purchaser approval may be blanket or may be issued on a case-by-case basis, as agreed. Unless otherwise agreed, the heat treat cycles employed; times, temperatures, rates, quenchants, etc.
Unless otherwise agreed, any separately cast test specimens or any removed from the castings, must accompany the castings they represent as part of the same heat treatment lot s or be subjected to the same thermal cycle as the castings they represent, in all respects. Microstructure 4. The matrix microstructure shall consist of ferrite, ferrite and pearlite, pearlite, tempered pearlite, or tempered martensite, or a combination of these.
The microstructure shall be substantially free of primary cementite. The microstructure shall be substantially free of undesirable carbides, the details of which are agreed upon between the casting manufacturer and the purchaser. Examples of matrix microstructures for each grade are shown in Fig.
Quality Assurance It is the responsibility of the manufacturer to demonstrate process capability. The specimen s used to do so shall be of a configuration and from a location agreed upon between the manufacturer and the purchaser.
Sampling plans shall be agreed upon between the manufacturer and purchaser. The manufacturer shall employ adequate controls to ensure that the parts conform to the agreed upon requirements. Minor imperfections usually not associated with the structural functioning may occur in castings. These imperfections are often repairable; however, repairs should be made only in areas and by methods approved by the purchaser.
Purchaser and manufacturer may agree to additional casting requirements, such as manufacturer identification, other casting information, and special testing. These should appear as additional product requirements on the casting drawing. Notes Marginal Indicia 8. An R symbol to the left of the document title indicates a complete revision of the report. The spheroidal graphite structure is produced by alloying the molten iron with small amounts of one or more elements such as magnesium or cerium.
The matrix microstructure may be controlled by addition of other alloying elements, such as: copper, tin, nickel, chromium and molybdenum. The relative amounts of each of these constituents is dependent upon the grade of material specified, casting design as it affects cooling rate, and heat treatments, if any.
The matrix microstructure of as-cast ductile iron depends to a great extent on the solidification rate and cooling rate of the casting.
If a section solidifies rapidly, especially sections of 0. If a section cools slowly, as in a massive, heavy casting, a largely ferritic matrix may result. Alloying elements also can alter the microstructure, usually resulting in increased amounts of pearlite.
Large variations in structure can be eliminated or minimized by modifying the casting design or the runner system or both, by controlled cooling, or any combination of these.
A rim may occur on heat-treated castings consisting of a graphite-free layer sometimes containing more or less combined carbon than the underlying material. The annealing time and temperature cycle is such that primary carbides, if present in the as-cast structure, are decomposed, and the resulting matrix is ferritic. D D is ferritic ductile iron supplied either as-cast or heat-treated. The matrix, is predominantly ferrite, but this grade can contain pearlite, depending on section size.
D D is ferritic-pearlite ductile iron supplied either as-cast or heat-treated. The matrix, is essentially pearlite. This grade may contain substantially more ferrite than Grade D D D is pearlitic-ferritic ductile iron supplied either as-cast or heat-treated. This grade may contain less ferrite than D D D is either as-cast or air quenched to a specified hardness range.
The resulting matrix is pearlite. D is either as-cast or air or liquid quenched and tempered to a specified hardness range.
The resulting matrix is pearlite or tempered martensite. The resulting matrix is tempered martensite. Since properties may vary with location in a given casting, the suitability of a particular grade for an intended use is best determined by laboratory or service tests. The mechanical properties will vary with microstructure that, especially in the as-cast condition, is dependent upon section size as well as chemical composition and some foundry processes.
Typical un-notched Charpy impact energy properties are shown in Table A2. These typical results are from low residual element content iron especially phosphorus. Impact values are affected by microstructure and section size. D D is used for moderately stressed parts where machinability is less important. D D is used for more highly stressed parts.
Additional Information A. ASM Metals Handbook. Iron and Steel. Ninth Edition. Ductile Iron Data for Design Engineers. Published by Q. Application This SAE standard covers the minimum mechanical properties measured on separately cast test pieces of varying thickness and microstructural requirements for ductile iron castings used in automotive and allied industries.
SAE J434 Grade D5506 ferritic, pearlitic
Characteristics of Ductile Iron 1. Ductile iron castings offer a wide range of mechanical properties: The ductile iron family offers the designer and engineer a unique combination of strength, wear resistance, fatigue resistance, and toughness, as well as excellent ductility characteristics. Tensile Strength: The tensile strength of ductile iron begins where gray iron stops. The as-cast tensile strength of ductile iron ranges from 60, to , psi Yield Strength: The yield strength of A ductile iron is a minimum of 40, psi.
SAE J434 for Automotive Ductile (Nodular) Iron Castings
Introduction The purpose of standard specifications for Ductile Iron castings is to provide a body of information which can be used with confidence by both designer and foundry to select, define and agree upon a set of specific properties which will ensure that the castings meet the intended use of the designer. It is the responsibility of both the designer and the foundry to be aware of the role and the limitations of specifications and to agree upon a specification that provides the optimum ratio of performance to cost. It is up to the designer to specify a set of properties - mechanical, physical, chemical or dimensional - which best suit the casting to its purpose. Once the specification has been selected, the foundry must ensure that all castings delivered meet or exceed the specification.