ASTM A959-19 pdf free.Standard Guide For Specifying Harmonized Standard Grade Compositions For Wrought Stainless Steels.
ASTM A959 provides a guide to ASTM Subcommittees A01.06, A01.10, A01.17, A01.22, and A01.28 for specifying chemical composition limits of wrought stainless steels. It is intended that these recommended grade composition limits be suitable for adoption by other standardization bodies that prepare standards for stainless steel products.
1.2 Included in this guide are the recommendations for determining the number of significant figures for specifying chemical composition from Test Methods, Practices, and Terminology A751.
1.3 All stainless steel UNS numbers and the stainless steel grades in all standards overseen by the aforementioned ASTM subcommittees have been included, except those grades applicable to restricted special end uses and alloys containing less than 10.5 % minimum chromium.
1.4 Not addressed are minor composition modifications which a specific product subcommittee may find necessary to accommodate effects of normal processing or to enhance fabricability by the producer or user, or both.
1.5 Also not generally addressed (except when established by ASTM product subcommittees) is a complete rationalization of all limits, especially when such would conflict with long-standing practices and is not justified by special technical effect.
1.6 Excluded from this guide are cast material and welding filler metal.
4. Significance and tJse
4.1 It is anticipated that the ASTM Subcommittees A() I .(. AOI.lO, AOl.17, AOl.22, and AOl.28 will use the standard composition limits listed in this guide for the grades identified by the corresponding UNS designation in the product specification unless there is a specific technical justification for doing otherwise. The compositions in this guide shall not he considered as chemical requirements for any particular product until adopted by the subcommittee overseeing that product.
4.2 Assuming that uniform compositions among the many product standards for stainless steel are desirable, the composition limits provided in this standard are to be used as guides in determining limits for each of the elements included in the total composition of each grade. The composition limits have been established with the intent that each product subcommittee will find it necessary to require only a minimum number of changes to reflect specific technical effects. Section 5 lists the general guidelines followed for determining the limits for each element: the limits established in this guide are based on these guidelines.
5. c;enrl Guidelines Used for Determining Composition limits
5. I C’arbon—lt is recommended that limits he to only two decimal places for levels of 0.04 % and higher because it is not necessary to control o such precision at levels above 0.04 %. (It should he recognized that limits such as 0.045 % maximum may also be simply stated as 0.04 % maximum.) It is also recommended that three decimal places be used at levels of 0.030 % and lower, unless, for exaniple. it is clearly recognized that 0.03 % maximum means that 0.035 % is satisfactory.
5.2 Manganese—Except for the Cr-Ni-Mn grades (S2XXXX). it is recommended that limits of 2 % maximum and I % maximum be used for the austeniüc and other grades respectively, except for the free machining grades with high sulfur or selenium, or when necessary to promote nitrogen soluhility.ASTM A959-19 pdf free.