Can SA516-70 be used in LPG environments?

This is equivalent to 16MnR in China, no problem at all.

It should be SA516-Gr70; it can be used in liquefied petroleum gas environments at temperatures not lower than -46 degrees. Last edited by scholar on 2008-4-18 21:16.]

Personally, it is not recommended for use with liquefied petroleum gas for the following reasons: the hydrogen sulfide content is difficult to control, which can cause SSCC.

SSCC should be a hydrogen sulfide stress corrosion environment, right? Personally, I don’t think it’s a big deal; it can still be used. I haven’t seen the foreign standards, so I’m not sure what the regulations are. Let’s use 16MnR as a comparison for now. In terms of China alone, although both the tolerance specifications and HG20581 outline what needs to be taken into account in environments subject to hydrogen sulfide stress corrosion, I think 16MnR can be used just fine, and there are many examples of its application. Of course, in cases of stress corrosion, it’s better to choose materials with lower stress levels. Then I guess SA516-70 should be available as well.

NACE’s MR0175-97 standard \"Materials for Oilfield Equipment Resistant to Sulfide Stress Cracking\": (1) Acidic gas environment: total gas pressure ≥ 0.4 MPa, and H2S partial pressure ≥ 0.0003 MPa； ⑵ Acidic multiphase system: When the crude oil being processed contains two or three phases (oil, water, gas), the conditions can be relaxed to: total gas pressure ≥ 1.8 MPa and H2S partial pressure ≥ 0.0003 MPa ； When the gas phase pressure ≤ 1.8 MPa and the H2S partial pressure ≥ 0.07 MPa ； Or the H2S content in the gas phase exceeds 15%. “An environment with both water and hydrogen sulfide is referred to as a \"wet hydrogen sulfide environment\" when the partial pressure of hydrogen sulfide is 0.00035 MPa or higher, or in liquefied petroleum gas containing both water and hydrogen sulfide when the hydrogen sulfide content in the liquid phase is 10×10-6 or higher. However, the hydrogen sulfide content changes with variations in oil quality, making it quite unstable. It’s hard to generalize. This post was last edited by jyszyx on 2009-3-31 15:05]

Since those upstairs are familiar with this standard, what material should be used? SA516-70N or SA516-70 (HIC)? Thank you

;P It can’t be generalized – you need to check whether your liquefied petroleum gas is in an environment subject to wet hydrogen sulfide stress corrosion

SA516-Gr70(HIC) is equivalent to !6MnR as a steel used for hydrogen-induced cracking tests, and can be used in environments containing hydrogen sulfide. This is imported steel, no problem. HIC – Hydrogen Induced Cracking: 1. S≤0.004%, P≤0.015%, C≤0.2; 2. Tensile strength σb (Mpa): 470–590; 3. Delivered in normalized condition; 4. The test method for resistance to hydrogen induced cracking (HIC) is in accordance with NACE TM-0284. It is mainly used for equipment that comes into contact with hydrogen and does not have a lining, and is frequently utilized under hydrogenation conditions.

Of course, we have done one for foreigners before using this material

This is excellent material, better than 16MnR. This material is also used for surface engineering equipment in hydrogen sulfide-rich gas fields, with strict limits on the S and P contents.