API Std 20G pdf download

API Std 20G pdf download Heat Treatment Services—Batch Type for Equipment Used in the Petroleum and Natural Gas Industry
1 Scope
1.1Purpose
This standard identifies requirements for heat treatment supplier qualification, processing, identification andtraceability, and documentation of heat treatment services for use in the petroleum and natural gas industrieswhen referenced by an applicable equipment specification.
1.2Applicability
The requirements of this standard apply to batch heat treatment operations that establish or affect the finalmechanical properties and include stress relief operations. This standard applies to carbon steel, low-alloysteel, stainless steel, and nickel-base alloys.Case hardening, induction hardening, and flame hardening are notcovered by this standard.
NOTE This standard does not limit the responsibility of any manufacturer of commercial products using batch heattreating services and manufactured to an APl standard from its responsibility for compliance with all applicable requirementsof that APl standard.
1.3Heat Treatment Specification Levels (HSLs)
This standard establishes the requirements for three heat treatment specification levels (HSLs). These HSLdesignations define different levels of heat treatment technical, quality, and qualification requirements.
2Normative References
The following documents are referred to in the text in such a way that some or all of their content constitutesrequirements of this document. For dated references, only the edition cited applies. For undated references, thelatest edition of the referenced document (including any addenda) applies.
API Specification Q1，Specification for Quality Management System Requirements for ManufacturingOrganizations for the Petroleum and Natural Gas industry
IsO 9001 1,Quality Management Systems — RequirementsSAEAMS2750 2, Pyrometry
3Terms, Definitions,Acronyms, and Abbreviations
For purposes of this standard, the following terms, definitions, acronyms, and abbreviations apply.3.1 Terms and Definitions
3.1.1
acceptance criteria
Defined limits placed on characteristics of materials, processes, products, or services.
3.1.2
case hardening
Ageneric term covering several processes applicable to steel that change the chemical composition of the surfacelayer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient.The result is a thin layer on the surface that is harder than the metal beneath it. The processes commonly usedare carburizing and quench hardening, cyaniding, nitriding,and carbon nitriding.
3.1.3
certification
Review and confirmation of all heat treatment processes to meet the order requirements.
3.1.4
final inspection
The final visuall examination of the heat-treated material.
3.1.5
flame hardening
A process for hardening the surfaces of hardenable ferrous alloys in which an intense flame is used to heat thesurface layers above the upper transformation temperature, whereupon the work-piece or area of the surfacethat has been heated by direct flame impingement is immediately quenched.
3.1.6
heat sink
Metal of a defined cross section and similar heat transfer characteristics to the part(s) being heat treated andused to monitor the heat treatment temperature by the use of an embedded thermocouple.
3.1.7
heat treat
heat treatment
Specified, timed sequence of controlled heating and cooling of materials for the purpose of changing physical ormechanical properties.
3.1.8
induction hardening
A surface hardening process in which only the surface layer of a suitable ferrous work-piece is heated byelectromagnetic induction to a temperature above the upper critical temperature and immediately quenched.
3.1.9
marking
ldentification placed on the heat-treated material in accordance with this standard.
3.1.10
on-site activity
Activity performed at the heat treatment supplier”s facility.
3.1.11
receiving verification
lnspection and review of incoming material and attendant documentation.
3.1.13
working zone
Usable volume of a furnace as determined by the temperature uniformity survey.
3.2Acronyms and Abbreviations
HSL
heat treatment specification level