API RP 934-E-2010 pdf free download

API RP 934-E-2010 pdf free download.Recommended Practice for Materials and Fabrication of 1 1 / 4 CR- 1 / 2 Mo Steel Pressure Vessels for Service Above 825 °F (440 °C).
5.1.2 All external attachments such as lugs, clips etc. welded directly to the pressure boundary shall be of the same material as the pressure boundary material. 5.1.3 Nozzles shall be manufactured from forgings. For thicker nozzles, 2 1 / 4 Cr-1Mo may be used to ensure that toughness requirements are met. When using 2 1 / 4 Cr-1Mo, appropriate weld procedures with higher preheat, PWHT temperatures, etc. should be used. Welding procedures should be approved by the purchaser. 5.2 Steel Making Practice In addition to the steel making practice outlined in the applicable specifications, the steels shall be vacuum degassed. 5.3 Chemical Composition Limits For 1 1 / 4 Cr- 1 / 2 Mo steel and 1Cr- 1 / 2 Mo, all plate, piping, and forging materials should be made to fine grain practice. The steel shall meet the following additional chemical requirements by heat analysis. C = 0.15 wt % max P = 0.012 wt % max S = 0.007 wt % max Cu = 0.20 wt % max Ni = 0.30 wt % max Nb = 0.004 wt % max V = 0.025 wt % max Ti = 0.02 wt % max also: X-bar ≤ 15 ppm where X – bar = (10P+5Sb+4Sn+As)/100 [with P, Sb, Sn, and As in ppm]
NOTE The J-factor is not applicable to these alloys, and an X-bar limit has been adopted as a means of restricting the concentration of elements that contribute to reheat cracking of the steel. The chemistry restrictions described above along with other aspects of this RP are designed to provide the steel with resistance to the reheat cracking phenomenon described in API 938-A. 5.4 Heat Treatment All product forms shall be annealed, normalized and tempered (N&T) or quenched and tempered (Q&T) to meet the required mechanical properties. For thickness > 2 in. (50 mm), Q&T may be required to meet fracture toughness specifications for the steel. Annealed steel and lower Class levels should be specified for applications involving high temperature service where the primary failure mechanism is creep rupture. For equipment exposed to cyclic service and where fatigue is an important factor the use of N&T or Q&T heat treatment and higher class levels may be more appropriate. 5.5 Mechanical Properties 5.5.1 Location of Test Specimens Test specimens for establishing the tensile and impact properties shall be removed from the following locations: a) Plate—From each mother-plate with the same heat treatment, transverse to the rolling direction in accordance with SA-20 at the standard test locations and at the 1 / 2 T location. When permitted by the applicable product specification, coupons for all tests shall be obtained from the 1 / 2 T location only. If required, 1 / 2 T specimens shall be used for hot tensile tests. NOTE If multiple plates are cut from one motherplate only one set of specimens from the motherplate is required. b) Forging—From each heat transverse to the major working direction in accordance with SA-182 or SA-336, and test specimens shall be taken at 1 / 2 T of the prolongation or of a separate test block. 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 filler wires, and each combination of filler wire and flux, shall match the nominal chemical composition of the base metal to be welded. 6.1.2 The following chemical composition limits shall be controlled to improve resistance to reheat cracking. The chemical composition restriction applies to the heat analysis. X-bar = (10P + 5Sb + 4Sn + As) / 100 ≤12 where P, Sb, Sn, and As are in ppm C is 0.15 % maximum Cu is 0.20 % maximum Ni is 0.30 % maximum 6.1.3 Low hydrogen welding consumables, including fluxes, having a maximum of 8 ml of diffusible hydrogen for every 100 g of weld metal, per AWS A4.3, shall be used. They shall be baked, stored, and used in accordance with manufacturer’s instructions (holding in electrode oven, length of time out of oven, etc). 6.2 Mechanical Requirements 6.2.1 Tensile Properties The tensile properties of the deposited weld metal shall meet those of the base metal in accordance with 5.5.2. 6.2.2 Impact Properties Prior to the start of fabrication, each lot of electrodes, heat of filler wire, and combination of lot of flux and heat of wire, shall be screened by impact testing of weld deposit in accordance with 5.5.3. 7 Welding, Heat Treatment and Production Testing 7.1 General Welding Requirements 7.1.1 Base metal surfaces prior to welding or applying weld overlay shall consist of clean metal, prepared by machining, grinding or blast cleaning.