New Style boiling exchanger equipment within the sequence of erosion and security facilities
When the device is subjected to hydrogen sulfide corrosion and tubes, there are a lot of black iron sulfide corrosion product accumulation. These phenomena can be observed in the field. As the production system or the role of oxygen in the atmosphere, the corrosion product is mixed with yellow sulfur, which is in the macro photo （eg 1 and） observed in the cause corrosion product was brown.
Condensing system shell weld stress corrosion cracking as described above, the heat exchanger welded joints more or Expansion form, because the process of welding and Expansion residual stress exists in the tube, the outer wall tensile stress exists. Tube sheet welding joints due amine and hydrogen sulfide and equipment residual stress after welding the joint action is very sensitive to stress corrosion cracking.
Especially when the ambient temperature exceeds o ℃ parts more susceptible to brittle fracture. Iron in the male 2-S-Yao Yao O solution, not only by the anode reaction of the corrosion products I seven S, cathodic reaction of hydrogen can penetrate into the steel and spread, causing embrittlement and hydrogen bubbling steel also occurs mainly due to sulfide stress corrosion cracking.
E7 （X n top of the tower reboiler heat exchanger shell of 16Mn low-alloy steel （shell without stress relieved after welding）, bundle of 20 gauge steel. Through the above analysis, the reasons causing stress corrosion, can be recognized as a play to persuade two S-O's caused by sulfide stress corrosion cracking.
Conclusions and measures （1） In the E7 to the top edge of the tower n reboiler heat exchanger happens is that S-502 a Yao Long 0 corrosion, namely electrochemical corrosion. The system is caused by corrosion is mainly sulphide.
（2） Physical tests showed that in addition to tube wall surface rust and residue five residues in addition there are a few I beg people and a small amount of Si Qiu, Cazsi, and I beg a few larger diffraction intensity peak.
（3） After the equipment should be carried out post-weld heat treatment to eliminate the welding residual stress, should control the weld and heat affected zone hardness HB2 （X）.
（4） In order to prevent the condenser temperature vulcanized pitting and crevice corrosion, tube and tube plate connection should adopt inflation encryption strength welding and weld strength affixed inflation.
（5） sulfur recovery unit timber available A3R, 16MnR and 20 gauge steel, engraved charge if corrosive conditions, and the bundle surface temperature exceeds 110 ℃， it is recommended to use Icd8NigTi austenitic stainless steel is appropriate.