ASTM A860 SPECIFICATION

Scope :

1.1 ASTM A860 specification covers wroughthigh – strength ferritic steel butt-welding fitting of seamless and electric and fusion-weldedconstruction covered by the latest revision of ASME B16.9 and MSS-SP-75 .Butt-welding fittings differing from these ASME and MSS standards shall be furnishedin accordance with Supplementary Requirements S58 of specification A960/A960M . These fittings are for use in high – pressure gas and oil transmission and distribution system .

Process

The material for fittings shall be fully killed fine – grain material made by a melting process that is intended to producer ounded , well dispersed , fine sulphide inclusions , that promote good notch toughness , assists in the  resistance to hydrogen induced cracking ,and for weldability suitable for field welding .

All butt – weld tees manufactured by cold –forming methods shall be liquid penetrant or magnetic particle examined by one of the specified in supplementary Requirements S69 or S70 of Specification a960/A960M . this examination shall be performed in accordance with a written procedure and shall be performed after final heat treatment . only the side wall area of the test needs be examined . this area is defined by a circle that covers area from the weld bevel of the branch outlet to the center line of the body or run . Internal and external surface shall be examined when size permits permits accessibility . No cracks shall be permitted . other imperfections shall be treated in accordance with 12.1 on finish . After the removal of any cracks , the tees shall be re-examined by the removal of any Acceptable tees shall be marked with the symbol PT or MT , as applicable , to indicate compliance . NDE personal shall be qualified in accordance with SNT-TC-1A .

Heat Treatment :

All fittings shall be furnished in the heat-treated condition . fittings formed above the transformation temperature orupon which welding is performed , ASTM A860/A860M-09 shall be cooled to below the lower critical temperature prior to heat treatment . Fittings shall subsequently be heat treat edby normalizing , quenching , and tempering or stress relieving in accordance with specification A960/A960M

ASTM A860 Fittings Chemical Requirements table 1

ASTM A860 Fittings Chemical Composition :

1. The chemical composition of the steel shall conformed to the requirements prescribed in Table 1 .
2. The steel shall not contain any unspecified elements for the ordered grade to the extent that it conformed to the requirements of another grade for which that element is a specified element having are quired minimum content .
3. Analysis of each heat of steel shall be made from a sample taken preferably during the pouring of the heat . There sults shall conform to Table 1 for either heat or specification A960/A960M for product analysis limits as applicable .
4. The fittings manufacturer shall make a product analysis per heat from either the starting material or from a fitting . The chemical composition thus determined shall conform to Table 1. The product analysis shall be the basis for rejection . for referee purposes , Test Method , Practices, and Terminology A751 shall Apply .
5. The carbon equivalent of the base metal, as terminology A751 shall apply . CE = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15.
6. weld metal used in the construction ofthe fittings shall conform to the tensile and impact requirements of 9.4 and 8.1 after heat treatment in accordance with Section 6 .A chemical analysis shall be performed on deposited weld metal for each heat of filler metal or , for submerged arc welding , each heat of filler metal and batch of flux the weld metal shall be deposited in accordance with the qualified weld procedure .
7. Only the carbon content of the deposited weld-metal composition need comply with the requirements of table 1 .The nickel content of the deposited weld metal shall not exceed 1.0 % .

ASTM A860 Fittings Mechanical Properties