INVESTIGATION OF THERMAL SPRAY CORED WIRES RESISTING H₂S STRESS CORROSION

Sulphide stress-corrosion cracking is very urgent problem in oil and chenical indus- try,gas division.To solve this problem,two kinds of cored wires,Fe-Cr course and Al course,for thermal spray were made,and with arc wire spray technique,intermetallic matrix conposite coatings were got. Adhesive strength tests show the adhesive strengths of Fe-Cr course coatings are higher than them of Al course. Diffusion H amount tests show that complete capacity,spissitude capacity, and adsorption capacity of coatings have great effects on descenting H diffusion.Nothing but complete and dense coatings can prevent H diffusion The results show that capability of ZH4 coating is the best,the next is ZH6 coating. tress corrosion process is that under the action of stress and dissolvent, metal forms apertures or crack soures,hereafter cracks gradually spread,and finally flaw.SSCC is typical low stress tardy crack.the results show the effect of ZH4 coating is the best. Coating is one of the most effective methods of preventing sulphide stress- corrosion cracking.Two courses of thermal-spray materials were applied on the surrace of tensile specimens.Steels can be separated from wet H2S by coatings to prevents atomic-hydrogen penetration, the results show that the SSCC resistance of steels was improved by plasma-sprayed coatings.The SSCC resistance of ZH4 coating is best.