Effect of Postweld Heat Treatment on the Sulfide Stress Cracking of Dissimilar Welds of Nickel-Based Alloy 625 on Steels

被引：8

作者：

Dai, Tao ^{[1
]}

Thodla, Ramgopal ^{[2
]}

Kovacs, William, III ^{[2
]}

Tummala, Kavitha ^{[2
]}

Lippold, John ^{[3
]}

机构：

[1] Oak Ridge Natl Lab, 1 Bethel Valley Rd, Oak Ridge, TN 37830 USA

[2] DNV GL Inc, 5777 Frantz Rd, Dublin, OH 43017 USA

[3] Ohio State Univ, Welding Engn Lab, 1248 Arthur E Adams Dr, Columbus, OH 43221 USA

来源：

CORROSION | 2019年 / 75卷 / 06期

关键词：

heat treatment; nickel alloy; steel; sulfide stress cracking; weld; PIPELINE STEEL; HYDROGEN; MICROSTRUCTURE; CORROSION; H2S; PERMEATION; RESISTANCE; BEHAVIOR; TENSILE;

D O I：

10.5006/3081

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Alloy 625 overlay on 2.25Cr-1Mo (F22) Steel or AISI 8630 is used in oil and gas industry for corrosion protection. In some cases, F22/625 or 8630/625 interface is possibly exposed to the H2S-containing production fluid and there is a risk of sulfide stress cracking (SSC). The postweld heat treatment (PWHT) is used to reduce the cracking susceptibility of the F22/625 or 8630/625 dissimilar metal weld (DMW). The effect of PWHT on SSC resistance was investigated using four-point bend tests in a pH buffered brine solution with 8.2 wt% H2S. PWHT was found to improve the SSC resistance. The F22/625 DMW was more resistant to SSC than the 8630/625 DMW. The SSC of DMW between Alloy 625 and steel can be understood as a combination of stress corrosion cracking and hydrogen assisted cracking. It proved that the hardness requirement 250 Vickers hardness number (VHN) mandated in NACE Standard MR0175/ISO 15156 is overly conservative and the hardness can be increased at least to 275 VHN to 280 VHN.

引用

页码：641 / 656

页数：16