Pressure vessel nondestructive testing technique--eddy current testing technique

Summarized pressure vessel uses tube production and eddy current testing technique  in process of using pressure vesse,including ferromagnetic steel tube and nonferromagnetic metal tube  eddy current testing technique in manufacturing process。

In using ferromagnetic steel tube far field eddy current testing technique 、nonferromagnetic metal tube eddy current testing technique and metal pressure vessel shell welding joint surface crack plane analysis eddy current testing technique。   Key words :eddy current test tube welding joint.

Heat exchanger is one of most common see pressure vessel,mainly used to oil、chemical engineering、supplying heat and so on Heat exchange between the working medium in the process of production, heat exchange mostly used structure is shell and tube，heat exchange tube is one of accessories of necessary to equip,by heat exchange tube can make different medium up to quantity of heat exchanged quickly。Usually, tube and shell in heat exchange equipped with flow high temperature,high pressure,inflammable,explosive and poisonous medium，so control new heat exchange tube quality and constantly inspect corrosion  washout and wall thickness reduction flaw,they are necessary for heat exchange to safe operation。Commonly used heat transfer metal tube including ferromagnetic carbon steel and alloy steel tube and nonferromagnetic stainless steel、copper and copper alloy pipe,aluminum and aluminum alloy tube,titanium and titanium alloy and so on，currently domestic and overseas test these metal tube use most common method is eddy current testing method，according to metal tube magnetism feature and testing phase then divided into ferromagnetic steel tube eddy current testing method in manufacturing process、manufacturing process nonferromagnetic metal tube eddy current testing technique,in using ferromagnetic steel tube far dield eddy current testing technique and nonferromagnetic metal tube eddy current testing technique。 Currently domestic and overseas commonly uses is manufacturing process every kinds of metal tube eddy current and set as follows testing standard:

GB/ T 5126  aluminum and aluminum alloy cold draw thin-wall tube eddy current flaw detection method

GB/ T 5248  copper and copper alloy seamless tube eddy current flaw detection method

GB/ T 7735   steel tube eddy current flaw detection method

GB/ T 12604. 6  nondestructive testing term  eddy current testing

GB/ T 12969. 2  titanium and titanium alloy tube eddy current testing method

GB/ T 14480  eddy current flaw detection system properties testing method

JB 4730    boiler ,pressure vessel and pressure tube nondestructive testing

Currently used more is heat exchange nonferromagnetic metal tube eddy current testing ,but heat exchange ferromagnetic steel tube eddy current testing work is just beginning，but these two are have no existing testing standard，currently JB 4730 revised draft the sixth part has been added to these two contents。 Overseas have mature standard in above four aspects，most reppresentative is American ASM E boiler pressure vessel V chapter eddy current test，including manufacturing process ferromagnetic steel tube  eddy current testing technique,manufacturing nonferromagnetic metal tube eddy current testing technique and use nonferromagnetic metal tube eddy current 。Canada sets far field eddy current testing standard on using ferromagnetic steel tube.