Good morning Dinesh, or whatever time it is where you are. Based on a quick reviews of the spec I think ASTM A179 would comply with NACE MR0175 (2002) which specifies materials that are resistant to sulfide stress cracking (SSC). ASTM A179 addresses seamless low carbon steel tubing that was cold drawn followed by a 1200F heat treat to obtain a maximum hardness of 72 HRB. Nickel is not a delibrate alloying addition to A179 steel tubing. NACE MR0175 Section 3 on ferrous materials states the following: 3.2.1 All carbon and low-alloy steels are acceptable at 22 HRC maximum hardness provided they (1) contain less than 1% nickel, (2) meet the criteria of Paragraphs 3.2.2, 3.3, and Section 5, and (3) are used in one of the following heat-treat conditions: (c) normalized; (d) normalized and tempered; (a) hot-rolled (carbon steels only); (b) annealed; (e) normalized, austenitized, quenched, and tem- pered; or (f) austenitized, quenched, and tempered...
Section 3.2.2 states:
3.2.2 The metal must be thermally stress relieved following any cold deforming by rolling, cold forging, or another manufacturing process that results in a permanent outer fiber deformation greater than 5%. Thermal stress relief shall be petformed in accordance with the ASME Code," Section VIII, Division 1, except that the minimum stress-relief temperature shall be 595°C (1,IOO"F). The component shall have a hardness of 22 HRC maximum.
Section 3.3 states:
3.3.1 Free-machining steels shall not be used. Section 5 addresses fabrication processes, e.g. overlays, welding, etc. Best Regards, Dave --- On Fri, 3/13/09, dinesh verma <dineshverma08@rediffmail.com> wrote: From: dinesh verma <dineshverma08@rediffmail.com> |
No comments:
Post a Comment