SECTION 3.0 DEFINITION OF TERMS AND ABBREVIATIONS

Transcription

1 SECTION 3.0 DEFINITION OF TERMS AND ABBREVIATIONS 3.1 Terms Symbols and Abbreviations... 2

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3 September 2010 API Recommended Practice Terms Austenitic a term that refers to a type of metallurgical structure (austenite) normally found in 300 Series stainless steels and nickel base alloys Austenitic stainless steels the 300 Series stainless steels including Types 304, 304L, 304H, 309, 310, 316, 316L, 316H, 321, 321H, 347, and 347H. The L and H suffixes refer to controlled ranges of low and high carbon content, respectively. These alloys are characterized by an austenitic structure Carbon steel steels that do not have alloying elements intentionally added. However, there may be small amounts of elements permitted by specifications such as SA516 and SA106, for example that can affect corrosion resistance, hardness after welding, and toughness. Elements which may be found in small quantities include Cr, Ni, Mo, Cu, S, Si, P, Al, V and B Diethanolamine (DEA) used in amine treating to remove H 2 S and CO 2 from hydrocarbon streams Duplex stainless steel a family of stainless steels that contain a mixed austenitic-ferritic structure including Alloy 2205, 2304, and The welds of 300 series stainless steels may also exhibit a duplex structure Ferritic a term that refers to a type of metallurgical structure (ferrite) normally found in carbon and low alloy steels and many 400 series stainless steels Ferritic stainless steels include Types 405, 409, 430, 442, and Heat Affected Zone (HAZ) the portion of the base metal adjacent to a weld which has not been melted, but the metallurgical microstructure and mechanical properties have been changed by the heat of welding, sometimes with undesirable effects High Strenth low Alloy Steels (HSLA) - A family of low-carbon steels in which the strength levels are achieved by the addition of moderate amounts of alloying elements such as titanium, vanadium or niobium in amounts of less than 0.1 per cent. They can be are more sensitive to cracking during fabrication from hydrogen embrittlement (delayed cracking) or underbead cracking Hydrogen Induced Cracking (HIC) describes stepwise internal cracks that connect adjacent hydrogen blisters on different planes in the metal, or to the metal surface. No externally applied stress is needed for the formation of HIC. The development of internal cracks (sometimes referred to as blister cracks) tends to link with other cracks by a transgranular plastic shear mechanism because of internal pressure resulting from the accumulation of hydrogen. The link-up of these cracks on different planes in steels has been referred to as stepwise cracking to characterize the nature of the crack appearance Low alloy steel a family of steels containing up to 9% chromium and other alloying additions for high temperature strength and creep resistance. The materials include C-0.5Mo, Mn-0.5Mo, 1Cr-0.5Mo, 1.25 Cr-0.5Mo, 2.25Cr-1.0Mo, 5Cr-0.5Mo, and 9Cr-1Mo. These are considered ferritic steels Martensitic a term that refers to a type of metallurgical structure (martensite) normally found in some 400 series stainless steel. Heat treatment and or welding followed by rapid cooling can produce this structure in carbon and low alloy steels Martensitic stainless steel include Types 410, 410S, 416, 420, 440A, 440B, and 440C Methyldiethanolamine (MDEA) used in amine treating to remove H 2 S and CO 2 from hydrocarbon streams Monoethanolamine (MEA) used in amine treating to remove H 2 S and CO 2 from hydrocarbon

4 streams Nickel base a family of alloys containing nickel as a major alloying element (>30%) including Alloys 200, 400, K-500, 800, 800H, 825, 600, 600H, 617, 625, 718, X-750, and C Stress oriented hydrogen induced cracking (SOHIC) describes an array of cracks, aligned nearly perpendicular to the stress, that are formed by the link-up of small HIC cracks in steel. Tensile strength (residual or applied) is required to produce SOHIC. SOHIC is commonly observed in the base metal adjacent to the Heat Affected Zone (HAZ) of a weld, oriented in the through-thickness direction. SOHIC may also be produced in susceptible steels at other high stress points, such as from the tip of the mechanical cracks and defects, or from the interaction among HIC on different planes in the steel Stainless steel there are four categories of stainless steels that are characterized by their metallurgical structure at room temperature: austenitic, ferritic, martensitic and duplex. These alloys have varying amounts of chromium and other alloying elements that give them resistance to oxidation, sulfidation and other forms of corrosion depending on the alloy content. 3.2 Symbols and Abbreviations ACFM alternating current field measurement ASCC alkaline stress corrosion cracking ACSCC alkaline carbonate stress corrosion cracking AE acoustic emission AET acoustic emission testing AGO atmospheric gas oil AUBT automated ultrasonic backscatter testing BFW boiler feed water C 2 chemical symbol referring to ethane or ethylene C 3 chemical symbol referring to propane or propylene C 4 chemical symbol referring to butane or butylenes Cat catalyst or catalytic CDU crude distillation unit CH 4 methane CO carbon monoxide CO 2 carbon dioxide CVN charpy v-notch CW cooling water DIB deisobutanizer.

5 DNB Departure from Nucleate Boiling DEA diethanolamine, used in amine treating to remove H 2 S and CO 2 from hydrocarbon streams EC eddy current, test method applies primarily to non-ferromagnetic materials FCC fluid catalytic cracker FMR field metallographic replication H 2 diatomic hydrogen H 2 O also known as water H 2 S hydrogen sulfide, a poisonous gas HAZ Heat Affected Zone HB Brinnell hardness number HCO heavy cycle oil HCGO heavy coker gas oil HIC Hydrogen Induced Cracking HP high pressure HPS high pressure separator HHPS hot high pressure separator HVGO heavy vacuum gas oil HSLA high strength low alloy HSAS heat stable amine salts IC 4 chemical symbol referring isobutane IP intermediate pressure IRIS internal rotating inspection system K.O. knock out, as in K.O. Drum LCGO light coker gas oil LCO light cycle oil LP low pressure LPS low pressure separator LVGO light vacuum gas oil MDEA methyldiethanolamine.

6 MEA monoethanolamine mpy mils per year MT magnetic particle testing NAC naphthenic acid corrosion NH 4 HS ammonium bisulfide PMI positive materials identification PFD process flow diagram PT liquid penetrant testing RFEC remote field eddy current testing RT radiographic testing SCC stress corrosion cracking SOHIC Stress Oriented Hydrogen Induced Cracking SS: Stainless Steel SW sour water SWS sour water stripper SWUT shear wave ultrasonic testing Ti titanium TOFD Time of flight diffraction UT ultrasonic testing VDU vacuum distillation unit VT visual inspection WFMT wet fluorescent magnetic particle testing.