API RP 934:2000 pdf download

API RP 934:2000 pdf download.Materials and Fabrication Requirements for 2-1/4Cr-1Mo &3Cr-1Mo Steel Heavy Wall Pressure Vessels for High Temperature, High Pressure Hydrogen Service.
a. Conventional steels: 100 ksi t690 N/mm2)
b. Advanced steels: 110 ksi (760 N/mm2)
Yield strength shall not exceed the following limits:
a. Conventional steels: 9() ksi (620 N/mm2)
h. Adsanced steels: 90 ksi (620 N/mm2)
5.5.2.2 Elevated temperature tensile tests, when required by the purchaser. shall be performed at the equipment design temperature. Test specimens shall be in the maximum PWHT condition. Acceptance values shall be as specified by the owner/user.
5.5.3 Impact Properties
5.5.3.1 Average impact values at —20°F (—29C) of three Charpv V-notch test specimens he-at treated in accordance with 5.5.1.2 shall not be less than 40 ft—lb (55 J) with no single value below 35 ft—lb (47 J). The percent ductile fracture and lateral expansion in mils shall also be reported.
5.5.3.2 Step Cooling Tests
5.5.3.2.1 Prior to the start of lubrication, step-cooling tests shall be pcrftnned on each heat of base metal to determine its susceptibility to temper embrittleinent. unless waived by the purchaser.
Two sets of Charpy V-notch test specimens, with a minimum of 24 specimens per set, shall he prepared and subjected to the following heat treatments:
Set 1—Minimum PWHT only. to establish a transition temperature curve before step cooling.
Set 2—Minimum PWHT plus the step cooling heat treatment specitIed in 5.5.3.2.3, to establish a transition temperature curve after step coling.
5.5.3.2.2 Step cooling heat treatment shall be as follows:
5.5.3.2.3 After the Charpy V-notch lest specimen sets are heat treated, each set of specimens shall be impact tested at eight selected test teniperatures to establish a transition temperature curve. One of the tests shall be perfornied at —20°F (—29°C) Three specimens shall he tested at each lest temperature. The transition temperature curve shall he established from at least two test temperatures on both the upper and lower shelf and a minimum of four intermediate test temperatures.
5.5.3.2.4 The 40 ft-lb (55 J) transition temperatures shall be determined from the transition temperature curves established from the two sets of Charpy V-notch specimens. The impact properties shall meet the following requirement:
CvTr4() + 2.5 DCvTr4() £ 50’F ( l0’C). where
CvTr4() = 4k) ft-lb (55 J) transition temperature of thc base metal subjected to the minimum PWHT only.
rCvTr4O = the shift of the 40 ft-lb (55 J) transition temperature of material subjected to the minimum PWHT plus the step cooling heat treatment.
6 Welding Consumable Requirements
6.1 MATERIAL REQUIREMENTS
6.1.1 The deposited weld metal. from each lot or batch of welding electrodes and each heat of tiller wires, and each combination of tiller wire and Ilux, shall match the nominal chemical composition (lithe base metal to be welded.
6.1.2 The following chemical composition limits shall be controlled to rninirniie temper embrinlenient.
X.bar(lOP+5Sh+4Sn+As)/ 1001.15
IP. Sb, Sn. and As in ppml
Cu: 0.20°/s maximum
Ni: 0.30% maximum
6.1.3 Low hydrogen welding consumables, including fluxes, having a maxinium of 10 ml of ditTusible hydrogen for evefy 100 grams of weld metal, per AWS A4.3. shall he used. They shall be baked and stored in accordance with manuftictitter’s instructions. i.e., electrode oven, to reduce moisture content and to ensure their low hydrogen nature.