Please see below a summary of the corrosion resistance properties of our core grades. Please be aware that corrosion resistance is a relative term, depending on media, operating conditions (pressure, temperature and many other factors). However all of these grades are included in the NACE International references of Petroleum and natural gas industries — Materials for use in H2S-containing environments in oil and gas production (MR0175-3 and the ISO equivalent – 15156-3).
The Rank “scores” below are as follows:
1=NOT APPLICABLE
2= GOOD TO VERY GOOD
3 = EXCELLENT
| Sulphuric Acid | Hydro-chloric Acid | Hydro-flouric Acid | Phosphoric Acid | Nitric Acid | Organic Acids | Alkaline Salts | Seawater | |
| MP35N | Outstanding crevice and stress corrosion resistance in hydrogen sulphide, salt water and other chloride environments, as well as from mineral acids (nitric, hydrochloric and sulphur). | |||||||
| Rank | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Alloy 286 / 660 | Good corrosion resistance at temperatures up to 700°C. | |||||||
| Rank | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 1 |
| Alloy 400 | Very good corrosion resistance, particularly stress corrosion cracking. | |||||||
| Rank | 3 | 3 | 2 | 3 | 3 | 3 | 3 | 3 |
| Alloy K500 | Good against sea water, and dilute hydrofluoric and sulphuric acids. | |||||||
| Rank | 3 | 2 | 3 | 3 | 1 | 3 | 3 | 3 |
| Alloy 625 | Resistant to aggressive media, resists crevice corrosion, stress & pitting corrosion. | |||||||
| Rank | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Alloy 718 | General good all round corrosion resistance. | |||||||
| Rank | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 |
| Alloy C276 | Resistant to reducing and mildly oxidizing environments, localised corrosion attacks & stress corrosion cracking. | |||||||
| Rank | 3 | 3 | 3 | 3 | 2 | 3 | 3 | 3 |
| Alloy 825 | Excellent resistant to sulphuric & phosphoric acids, resistant to reducing & oxidising acids, resistant to pitting, stress corrosion cracking, and inter-granular corrosion. | |||||||
| Rank | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| HTS 316 | Comparable corrosion resistance as Alloy 825, but with higher strength (in cold work hardened condition) | |||||||
| Rank | 3 | 3 | 1 | 3 | 3 | 3 | 3 | 1 |
| F55 | Outstanding corrosion resistance with a Pitting Resistance Equivalent at >= 40.0 which guarantees high resistance to pitting corrosion. High resistance to crevice corrosion and stress corrosion cracking. | |||||||
| Rank | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 3 |
If you have any questions on the applicability of our stock grades in particular circumstances, or what you can do to reduce the risk of corrosion when handling metal, please do not hesitate to contact our Special Process department on +44 114 232 9243.
