1、ASME PTB-8-2014Procurement Guidelinesfor Metallic MaterialsPTB-8-2014 PROCUREMENT GUIDELINES FOR METALLIC MATERIALS Prepared by: Elmar Upitis Upitis however, such other codes have not been evaluated for inclusion in this document. PTB-8-2014: Procurement Guidelines for Metallic Materials 2 2 SCOPE T
2、he ASME Codes and material specifications include specific requirements for use of the materials in ASME Code construction. However, they do not address all requirements. It is the responsibility of the user to specify service related requirements to prevent in-service degradation of the materials.
3、It is the responsibility of the vessel manufacturer to account for materials degradation during fabrication and to include all necessary requirements in the raw material purchase specifications for ASME Code construction. The scope of this document is to discuss the requirements in the ASME Codes an
4、d in the ASME material specifications for metallic materials, to address the various issues that affect the materials, and to provide guidelines for evaluating materials manufacturers and for preparing materials specifications that include the requirements for procuring material for ASME Code constr
5、uction. Some of the sections in this document pertain only to ferrous materials (carbon steels, low alloy steels and high alloy steels) because many of the past problems have been related to these materials (refer to Section 4 and Section 11 herein). However, most of the issues and considerations di
6、scussed in this document also pertain to nonferrous materials, particularly Sections 12 14 herein. PTB-8-2014: Procurement Guidelines for Metallic Materials 3 3 ASME ADOPTION OF MATERIAL SPECIFICATIONS ASME material specifications are those that are published in the BPVC Section II, Parts A, B and C
7、. The majority of ASME material specifications are based on ASTM or AWS specifications. ASME ferrous material specifications are identified by the letters “SA” as the first characters in the specification number. For example, SA-106 refers to an ASME specification, whereas A106 refers to an ASTM spe
8、cification. ASME nonferrous material specifications are identified by the letters “SB” as the first characters in the specification number. For example, SB-366 refers to an ASME material specification, whereas, B366 refers to an ASTM material specification. ASME welding rod, filler metal, and electr
9、ode material specifications are identified by the letters “SFA” as the first characters in the specification number. For example, SFA-5.1/SFA-5.1M refers to an ASME specification, whereas, A5.1/A5.1M refers to an AWS welding material specification. As ASME adopts ASTM and other acceptable internatio
10、nal material specifications for pressure vessel construction, the requirements in the ASME specification generally will be the same as those in the adopted ASTM or the acceptable international specification. However, some of the ASME material specifications include a statement underneath the title o
11、f the specification that lists the exceptions from the ASTM (or international) specification, or additional ASME requirements. Users should consult the appropriate specification to determine the differences between the ASME and the ASTM/AWS (or other international) specifications. 3.1 ASME Material
12、Specifications In general, materials used for ASME BPVC construction are required to be ASME materials. The BPVC Section II, Part D, Tables 1A, 1B, 2A, 2B, C, 5A and 5B list all materials that may be used for ASME Code construction. Materials that have a temperature listed in the column titled “Appl
13、icability and Maximum Temperature Limits” may be used for ASME Code construction within the indicated temperature range for the applicable BPVC Section. Materials that have “NP” listed in this column may not be used for construction under that Section. Materials that are not listed in the BPVC Secti
14、on II, Part D, may be used for ASME Code construction if permitted by an ASME Code Case. The materials used for ASME Code construction must be furnished in accordance with the specifications listed in BPVC, Section II. The materials for Code use shall be ordered, produced, and documented in accordan
15、ce with either the ASME specification in Section II (except as limited by the rules of the applicable construction code), or with an ASTM specification listed in Table II-200-1, or with a specification issued by other acceptable non-ASTM (international) specifications listed in Table II-200-2, or in
16、 a ASME Code Case for the construction code(s) listed in the ASME Code Case. The ASME SA material specifications include a statement under the title of the specification that identifies the related ASTM or the international material specification. Many ASME SA material specifications are identical w
17、ith a particular edition of the same ASTM specification, in which case the ASME SA specification states that the ASME SA specification is identical with the ASTM or the international material specification, and lists the year date of the publication of that specification that is used for adoption of
18、 it as the ASME SA material specification. However, not all of the ASME SA material specifications are identical with the ASTM or the related international material specification. In such cases the statement under the title of the ASME SA specification also lists the exceptions, or modifications, or
19、 additional requirements to the adopted specification for use in ASME Code construction. For example, the ASME SA specification SA-335 adds hardness requirements for Grades P23 and P911 pipes. Another example is fusion welded pipes under specifications SA-671 and SA-672 that include an additional st
20、atement that limit fabrication of such pipe for ASME Section III PTB-8-2014: Procurement Guidelines for Metallic Materials 4 construction to Manufacturers holding the appropriate ASME Certificate of Authorization and Certification Mark. Also the ASME SB nonferrous material specifications include a s
21、tatement under the title of the specification that identifies the related ASTM or the international material specification. Some of the ASME SB material specifications are identical with a particular edition of the same ASTM specification, in which case the ASME SB specification states that the ASME
22、 SB specification is identical with the ASTM or the international material specification, and lists the date of publication of that specification that is used for adoption of it as the ASME material specification. However, most of the ASME SB nonferrous material specifications are not identical with
23、 the ASTM or related international material specification because many do not include the mandatory requirement for a certification and test report. In such cases the statement under the title of the ASME SB specification also lists the exceptions, modifications, or additional requirements, and incl
24、udes the statement that certification and test reports have been made mandatory for the adopted specification for use in ASME Code construction. 3.2 ASTM Material Specifications In general, materials used for ASME B31 Pressure Piping Code designs must be ASTM materials. The B31 Pressure Piping Codes
25、 contains table listings of ASTM materials that are for use within the scope of that Code. Each ASME Code also includes rules for the use of unlisted materials, whether such materials are ASTM, ASME, or produced to another material specification. For BPVC applications, BPVC Section II, Part A, Table
26、 II-200-1 and Section II, Part B, Table II-200-1 list the dates of the latest adopted ASTM material specifications and other acceptable ASTM specification editions that may be used in lieu of the corresponding ASME specifications, provided the additional requirements referenced in the subtitle are m
27、et. Likewise, Tables II-200-2 in Section II, Part A and in Part B list the latest and other acceptable editions of non-ASTM specifications that may be used in lieu of the corresponding ASME specifications, provided the additional requirements listed in the ASME specifications are met. ASTM specifica
28、tions may be used if listed in BPVC Section II, Part A, Table II-200-1, except as limited by rules in the applicable construction code. If the BPVC Data Report is registered with National Board, material specifications must be in accordance with ASME SA specifications. 3.3 Dual Marked Materials Occa
29、sionally, users may come across items that are marked as both ASME and ASTM materials. For example, a pipe may be marked as “A/SA-106” or “SA-106/A-106”, which indicates that the material complies with the requirements of both the ASTM specification and the corresponding ASME specification. Material
30、s marked in this fashion may be used in applications requiring either ASME or ASTM materials. PTB-8-2014: Procurement Guidelines for Metallic Materials 5 4 GENERAL REQUIREMENTS IN MATERIAL SPECIFICATIONS FOR VARIOUS PRODUCT FORMS A material specification for a product (plate, forging, pipe, etc.) in
31、cludes the specific requirements for materials produced to that specification, and often includes the following: Types, grades, or classes of material covered by the specification. General requirements and ordering information. Manufacturing practice. Heat treatment. Chemical composition requirement
32、s. Mechanical properties. Supplementary requirements considered applicable to the materials produced under that specification. Common requirements that are applicable for a particular product form (such as plate, forging, pipe, etc.) are frequently referenced in the general requirements section of a
33、 material specification. These general requirements specifications provide additional information that may not be stated in the specific material specification. General requirements specifications may typically include the following: Material specifications covered by the general requirements specif
34、ication. Ordering information that should be specified by the purchaser. Manufacturing requirements for the material. Heat treatments. Chemical composition (by heat and product analysis). Metallurgical structure. Quality requirements. Test methods. Tension test requirements. Notch toughness test req
35、uirements. Identification of the product forms (e.g., plates). Permissible variations in dimensions or mass. Inspection and testing. Provisions for retest. Provisions for re-heat treatment. Notch toughness test requirements. Rejection. Test reports. Marking. In some cases there are differences betwe
36、en the requirements of a material specification and the referenced general requirements specification. In these cases, the requirements of the specific material specification will prevail. The general requirements specifications also include a list of the supplementary requirements that are consider
37、ed suitable for use with the specific product specifications. The product specifications may include additional supplementary requirements that are suitable for a particular product specification. The general requirements specifications form an integral part of the specification of a material, and i
38、t is important that ASME Code users understand what is in these specifications, and how they impact the specification and procurement of materials. The following sections highlight some of the general requirements specifications for ferrous materials (carbon, low alloy, and high alloy steels) that A
39、SME Code users should be familiar with. PTB-8-2014: Procurement Guidelines for Metallic Materials 6 4.1 SA-20, General Requirements for Steel Plates for Pressure Vessels SA-20 includes general requirements for pressure vessel plate specifications that are listed in the Scope. That includes requireme
40、nts for terminology, ordering information, materials and manufacture, heat treatment, chemical composition, metallurgical structure, quality, test methods, tension tests, notch toughness tests, identification of plates, permissible variations in dimensions or mass, inspection and testing, retests, r
41、etreatment, rejection, test reports, and packaging, marking, and loading for shipment. The following are comments on several of these requirements: (a) Manufacture - Practically all steel in modern steel mills is now produced by strand casting. However, ingots are still used for producing thick plat
42、es. Strand cast slabs are limited to about 10 to 12 inches maximum thickness, which limits the final plate thickness to about 4 inches after reduction. SA-20 contains alternative rules that may be used to produce plate using strand cast slabs in thicknesses to about 6 inches. (b) Heat Treatment - Th
43、e heat treatment (normalizing, quenching and tempering, thermomechanical processing) is specified in the general product specification. ASTM and ASME specifications do not consider “normalized rolling” (permitted by the European (EN) specifications for pressure vessel plates) to be an acceptable sub
44、stitute for “normalizing”. (c) Chemical Composition - In addition to the elements specified in the applicable product specification, SA-20 requires determination of the content of the following elements: carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, copper, vanadium,
45、columbium, and in some cases aluminum or other austenitic grain refining element. The chemical composition may include other unspecified elements that may not be listed in the chemical composition tables of the product specification but, if present in excessive amounts can increase hardenability or
46、decrease weldability. SA-20 imposes maximum limits (SA-20 specifications, Table 1) for certain elements (copper, nickel, chromium, molybdenum, vanadium, columbium, titanium, and boron) that may be present but are not listed in the product specification. Excessive amounts of these elements can cause
47、martensitic hardening in heat affected zones during postweld heat treatment with a corresponding loss of notch toughness and can lead to an increased risk of hydrogen-delayed cracking. (d) Tension and Impact Testing - SA-20 includes detailed requirements for tension testing and impact testing most o
48、f which is referenced in the product specifications and is referred to the general requirements specification for testing requirements. (e) Quality - SA-20 includes specific requirements for defects and states that plates shall be free of injurious defects. It goes on to state that injurious surface
49、 imperfections shall be removed by the manufacturer or processor. Unfortunately, SA-20 does not define “injurious defects”, however it is generally understood that a plate with an “injurious defects” is not suitable for the intended service. Code users may want to consider adding a definition of injurious surface imperfections to their material specifications if it is critical to their application. SA-20 also includes acceptance criteria for edge defects. (f) Repair by Welding - SA-20 includes specific requirements for repair welding. Re
