RE: [MW:6143] HSLA Welding.

Just to add Metallurgy behind HSLA.

 

Metals and alloys get deformed when dislocations are forced to move by application of force.

Addition of small amount of carbide forming elements eg. Nb, V, Ti etc added total amount 0.20% max and this fine dispersion of alloy carbides will restrict the movement of dislocations and results in strengthening by precipitation hardening.

 

Regds/Jignesh

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From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of MOHAMED HEGAZY
Sent: Tuesday, July 27, 2010 1:44 PM
To: materials-welding@googlegroups.com
Subject: Re: [MW:6141] HSLA Welding.

Dear Limesh,     HSLA Steels are Microalloyed Steels formulated with small amounts of some alloying elements ( Niobium Nb, Vanadium V & Aluminum Al )to provide higher strength, better toughness & Weldability and in some cases greater resistance to specific corrosion mechanisms in specific environments than Ordinary Carbon Steels.   Usually used in as rolled or Normalized Conditions & rolling process is integrated in developing final Mechanical Properties. Special rolling practices such as Controlled Rolling known as Thermo Mechanical Controlled Processing TMCP had been devised for enhancing Mechanical & Metallurgical performance for this category of steels.   Typical Yield Strengths range is 40 up to 110 Ksi  & Typical Tensile Strengths range is 60 up to 120 Ksi .   Common Grades on API are: 5L Gr X 60,X 70 & X 80. Common Grades on ASTM are : A 353 , A 735 & A 736   I believe that both HSLA 65 & API X65 are the same.   Some Precautions to be taken during welding :   1-Preheat to be used based on Thickness, Carbon Equivalent & Welding Process….. 2-Low Hydrogen Practices (Proper cleaning, packaging for fillers & avoid any Hydrogen Contamination sources )     to be followed with ARC Welding Processes ( Gas shielded Arc Processes GTAW,GMAW or PAW  are Preferred rather than Slag Shielded Processes SMAW,SAW or FCAW ). 3-Cellulosic Electrodes can be used with some API Grades ( Low Carbon Content Grades ).     Thanks & Regards Mohamed.Hegazy QA QC Welding Engineer AWS Certified Welding Engineer CWEng. TWI CSWIP Welding Inspection 3.1. VSA Consortium ( VEOLIA, SAIPEM & Aljaber ) QATAR SHELL PEARL GTL Project Ras Laffan ,Qatar QATAR :  +9743694501  EGY:       +20142345614 Email       : MH_W_Inspect@Yahoo.COM  --- On Tue, 7/27/10, Ali Asghari <asghariali@rocketmail.com> wrote: From: Ali Asghari <asghariali@rocketmail.com> Subject: Re: [MW:6139] HSLA Welding. To: materials-welding@googlegroups.com Date: Tuesday, July 27, 2010, 9:32 AM these steel are refinement by adding microalloys such V,Al,Nb,Ti & thermo mechanically heat treatment to increse toughness & strength simultanously. HY-80,HY-100 & X-100 are examples of these steels. during of welding of these steels, the minimum H.I SHALL BE USED to prevent growth grain. From: limesh M <limesh78@gmail.com> To: Materials & Welding <materials-welding@googlegroups.com> Sent: Tue, July 27, 2010 10:15:16 AM Subject: [MW:6137] HSLA Welding. Dear All, I have heard a lot about of HSLA(High Strength Low Alloy) and it confusing me a lot. Can anyone give a proper defenition for HSLA steel ? What are all the common grades in API,ASME,ASTM,AISI comes under HSLA steel category ? HSLA-65 and API X65 are same material? What are all the precautions we have to follow during HSLA welding ? -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.