Tech 3 Skills PDF

Tech 3 Skills  Objectives Upon successful completion of this course you will be able to: Be able to access the mill face database Differentiate between a pass and a station Define the components and purpose of a mill face spacer Explain the different ways that shape ke...

Tech 3 Skills  Objectives Upon successful completion of this course you will be able to: Be able to access the mill face database Differentiate between a pass and a station Define the components and purpose of a mill face spacer Explain the different ways that shape keeps rolling mills aligned  Objectives Upon successful completion of this course you will be able to: Explain the purpose of the mill face alignment chart Understand proper outboard and mill bed condition Define all the components of a shaft and identify a shaft that is in good working condition Describe how to repair a mill bed in need of repair  Objectives Upon successful completion of this course you will be able to: Describe the purpose of the inboard and outboard keyways Define the purpose of the alignment of rolling mills Explain the steps of a raft alignment and the tools need to complete one Execute a raft alignment Define Reproducibility, Independent verification, and Data Availability  Objectives Upon successful completion of this course you will be able to: Explain the importance reproducibility Identify common issues in completing reproducibility properly Define your role in reproducibility as a tech 3 Describe cut and etch Explain what cut and etch is used for at shape Describe common failures in cut and etch preparation Explain the roll of properly polishing a coupon for examination  Objectives Upon successful completion of this course you will be able to: Define smearing as it pertains to cut and etch Describe what a proper sample looks like for cut and etch Explain what a crack is on a sample Establish a proper troubleshooting methodology Communicate the importance of making a single adjustment at a time Analyze a drawing for troubleshooting  Mill alignment A rolling mill is a piece of precision equipment. Keeping the stations of a rolling mill aligned is critical as it keeps the tooling aligned. As there are several different types of rolling mills at shape there are many different techniques that we use at shape to keep the stations of each of those types of rolling mills aligned.  Mill Face Alignment A three pass alignment is similar to a mill face alignment except we are only aligning one inboard stand A Raft Alignment is aligning the individual stations on rafts of a rolling mill A mill face alignment is aligning the entire rolling mill Pass – Each ordered pair of tooling Station – One stand on the rolling mill that can accommodate a pass  Mill Face Spacer Mill Face Spacer (machine face spacer) – a custom thickness spacer that keeps the shoulders of the shafts in a straight line Spacers remain with the rolling mill and are not removed during a tooling change These spacers normally have a flat cut in them Have the station number and shaft engraved in them Are through hardened Mill Face Spacer Station number and location (top or bottom) Spacers must have a chamfer on the inside diameter so there is no interference with the shaft shoulder (1/8” across the flat is ideal)  Shaft Shoulder Shaft Shoulder - The larger diameter of the shaft located on the inboard stand The shaft shoulder is the surface the mill face spacer rests against Examples of Shaft Conditions This shaft has chipped edges around the keyway. Under ideal circumstances, it is best to replace this shaft or the inboard stand. If it is not possible to replace, try using a longer a key when reinstalling the roll tooling This shaft has gouges which appear to be from a cutting torch. The shaft was buffed with a grinder and the tooling slides on the shaft without an issue and is not in need of replacement at this time  Shaft Threads If the shaft threads are not in good condition, make sure to get this taken care There is a die set that is used to chase the threads. A wire brush and files may also be used.  Items to Verify Check the outboard stands and make sure they slide on the shafts with minimal resistance. If they do not slide freely, check the following: Is the bottom of the outboard stand pitted, rusted, burred, etc? Is the mill bed in rough condition where the outboard stands slide? When the outboard stand is on the key that is on the mill bed, look through the bearing sleeves. Do the shafts look aligned with the sleeves?  Outboard Stands If you suspect the bottom of the outboard stand is the issue: 1. Safely lift the outboard stand 2. Using a rag, wipe the bottom of the stand looking for foreign objects like metal shavings or slugs. Do not forget to wipe the keyway since this area could also cause an interference. If you do not find anything wrong, move on to the next step  Outboard Stands 3. Look underneath the stand and check for pitting, rust, or anything that would interfere with the outboard stand sliding on the mill bed. Use a honing stone to correct any of these issues  Outboard Stands 4. On occasion a grinder is needed to smooth out the bottom of an outboard stand. If this is the case, make sure to take the time and smooth the bad spots out completely. Also, wipe the bottoms after grinding since there will probably be debris deposited by the grinding process 5. If you have gone through the steps and the outboard stand is smooth on the bottom, there must be another issue to look at  Mill Bed If the mill bed is in bad condition in the outboard base area: 1. Clean the mill bed using rags, squeegee, etc. 2. If there are burrs, use a honing stone to knock the high spots down 3. A grinder should not have to be used, but if so make sure to wipe the area after grinding so the debris left behind is removed 4. Now the outboard should slide freely on the key and mill bed  Alignment of Inboard Stand There are two keys on the mill bed to align the inboard and outboard stands Inboard key – aligns the inboard stands Outboard key – aligns the outboard stand and is perpendicular to the inboard key  Alignment of Inboard Stand As with any keyway, there is a tolerance designed into the keyways on the bottom of the stands This makes it possible for the inboard stand shafts to be slightly out of line with the outboard stand  Checklist Before We Begin Let’s go through a quick checklist before we begin setting up All of the roll tooling is off the station you are aligning The mill bed is clean The outboard stands are off the mill bed or in a safe location. We do not want to leave the outboard stands on the mill bed where they could fall on someone. Use caution and good judgment  Mill Face Database Before beginning, check the mill face database, located in plex. See if the rolling mill you are going to align is in the system. If it is, print the sheet and this will be useful as a comparison. If there is no record, print off a blank and fill the information in after the alignment. Once the alignment is complete, make sure the revised or created mill face chart is turned in to the RFE in your area This is an example of the mill face chart You can scroll through all of the mill face alignments in each building If you find the chart for the mill you are going to align, click on the print icon If there is no chart for the mill you are going to align, you will need to make one after you complete the alignment  Raft Face Alignment Just like our conventional mills our rafted mills also need to be kept in alignment. To do this we use the Raft face alignment kit. This method is used for rafts being placed on rolling mills that have had the mill beds aligned precisely.  Raft Face Alignment 1. Place raft cassette onto saw-horses for service, using 10k capacity fork truck  Raft Face Alignment 2. Unbolt and remove outboard stands from raft plate  Raft Face Alignment 3. Remove outboard stands from raft plates. If 1" adjustable stand is used on one of more stands the fork pocket will need to screw onto elevating screw.  Raft Face Alignment Ensure bottom shafts of each inboard stand are sufficiently tight. No up/down movement of the shaft is allowed! Tighten as needed, ensuring free rotation of the shaft is maintained while adjusting.  Raft Face Alignment 4. Install bottom shaft alignment tool (STDAT1497-3", STDAT1509-2") position location key “feet” of tool into inboard locating keyway at back of raft cassette plate. Tool must be pushed against the back keyway edge.  Raft Face Alignment 5. Install locking collar onto shaft, Slide collar against mill face spacer. Ensure collar is seated firmly against spacer and lock into place using cam lever (attached)  Raft Face Alignment Ensure bottom mill face spacer has been thoroughly cleaned and is reinstalled prior to installing locking collar  Raft Face Alignment 6. Zero out digital indicator against zero set block in alignment tool. Slide indicator into zero set bushing. Ensure indicator is fully seated against top shoulder of bushing.  Raft Face Alignment 7. Install indicator into measurement position bushing on alignment tool. Seat indicator shoulder firmly against head of collared bushing head  Raft Face Alignment 8. Read and record measurement of mill face spacer deviation. Indicator will measure positive/negative deviation from nominal position. Positive deviation indicates material to be removed from face of spacer. Negative measurement indicates material to be added (new, thicker spacer required)  Raft Face Alignment 9. Determine if mill face spacer needs to be ground or replaced. Deviation from indicator reading will dictate necessity to grind existing spacers. Nominal dimenson for millface spacer thickness is.500“. Large deviations from nominal (tk=.030" from nominal") was measured Top/Bottom Alignment Procedure 10. Using top and bottom rolls from std design (STDAT1497/1509) to determine top/bottom off-set of shaft alignment  Raft Face Alignment 11. Load top and bottom roll onto roll shafts. Top roll first! Top and bottom shaft spacer to be ground prior to roll installation to ensure proper flatness prior to performing top/bottom alignment procedure  Raft Face Alignment 12. Parallelism of top-bottom shaft. Load aluminum outboard onto top and bottom roll shafts. Move top/bottom rolls to shaft center. Adjust vertical screw on aluminum outboard until parallel measurement is obtained from outboard side of rolls to inboard side of rolls.  Raft Face Alignment 13. Install top-bottom alignment rolls, Slide rolls against top and bottom alignment spacers at inboard side. Rotate top and bottom rolls until the bottom indicator port location lines up with the outermost diameter of the top roll. Ensure both rolls are seated firmly against spacers prior to measuring.  Raft Face Alignment 14. Zero out digital indicator, Slide indicator against zero set block in bottom alignment tool zero set port. As a second option, it is also possible to lay both rolls onto a surface plate and zero the digital indicator from that surface.  Raft Face Alignment 15. Measure top-bottom alignment spacer deviation. Insert zeroed indicator into lower port hole to measure deviation between top and bottom alignment spacer thickness. Positive measurement value indicates material to be removed from face of upper alignment spacer. Negative measurement indicates material to be added (new, thicker spacer required)  Finishing the Alignment Now the raft has been aligned and all the correct spacers are installed All that is left to do to complete the alignment process is complete the Mill Face Line Up Chart and turn it in to an RFE or CRS  Reproducibility Reproducibility is the ability to reproduce the results of a process using the same materials and methods. It is the ability to be reproduced or copied. This is critical in a manufacturing environment because it gives operators who may be unfamiliar with a machine or process the ability to set up the machine or job with the information in the system.  Principles of Reproducibility Independent verification: The ability for others to repeat and obtain similar results, not requiring the same person. Data Availability: To achieve reproducibility operators should make their data detailed, complete, accessible, and up to date.  Importance of Reproducibility What are the dangers if we do not follow reproducibility? We could feed the wrong steel. Reproducibility begins when we unband a coil. Scrap would increase for every job set up, adjustments would increase, and the wrong adjustments could be made. Reproducibility affects all downstream settings; one missed step can cause a big issue. IE last pass not set to reproducibility will affect straightener/sweep to be out.  Importance of Reproducibility Equipment damage: setting a die in the incorrect position can cause a die to shift, setting a press to the incorrect shut height could damage the die and the press. It makes your job more difficult: The more adjustments made the more time you will consume. Creating more down time and overtime. Common Issues in Reproducibility No Date/Time Reproducibility must be completed as the setting is being performed not before or after Initial each box, no lines or other short cuts If you can not get a setting to work escalate it! Adjustments not filled in from results page Parts per adjustment not correct Adjustment notes not detailed Downtime issues not documented Common Issues in Reproducibility Target update not authorized by RFE Die change sheet vs non die change sheet Non die change sheet needs to be filled out. Escalate to create a die change sheet. Die change sheets followed completely Results page not completed No tech 3 or RFE signoff TM made adjustment before verifying Did not involve a tech 3  Reproducibility Your roll as a tech 3 is critical to our ability to evaluate and trouble shoot the process of reproducibility. Verifying then adjusting the process and troubleshooting processes that need adjustment is critical to keeping scrap rates low and Overall Equipment Efficiency. Reproducibility Trouble Shooting Reproducibility Trouble Shooting Reproducibility Trouble Shooting Reproducibility Trouble Shooting  Cut & Etch Cut and Etch is a destructive testing method used to evaluate the characteristics of a weld. The process involves cutting, polishing and etching a sample from the weld to reveal the weld’s profile and microstructure.  Cut & Etch The cut and etch test can reveal a weld’s penetration, porosity, cold lap and other material characteristics. It can also show defects such as a lack of fusion between layers in a multi-pass weld. The cut and etch test is a quick and effective way to evaluate welding techniques, parameters, gases, angles, travel speed, and more.  Cut & Etch A sample is cut from the weld (coupon) then ground and polished and then etched with a chemical reagent. Etching reveals the boundaries between the base metal (parent material), weld metal, and the heat affected zone (HAZ). It also shows the samples microstructure and flow lines. Weld inspectors can use etching to evaluate a weld for penetration, fusion, defects, and other material characteristics.  Cut & Etch process Cutting: a sample is cut from a weld coupon to expose the weld’s profile Polishing: the cut face of the sample is polished to create a smooth surface for viewing Etching: an acid-based solution is used to etch the surface and reveal more detail  Wet Saw When using the wet saw place the sample in the vice of the saw positioning the weld to be sectioned properly, and clamp the sample tightly. Lower the arm to cut the sample. Cut at a smooth, constant Arms Weight speed.  Wet Saw Cutting too fast or slow causes sharp flashing and burn marks to occur. It also wears down the blade. Uneven, sharp, flashing and hooks cause issues at the polishing station.  Inspect Sample Look at both sides of your sample to check for flatness, hooks, and or heavy flashing. If necessary, belt sand to remove burn marks beveling, hooks, or flashing from your sample that will be placed on your mat.  Polishing Replace pads if there are any rips/tears/holes in it or when you have a lack of abrasion. Pull off the mounting ring (inspect it as well) remove pad and replace by putting the mounting ring back on. Do Not peel off the plastic backing. Monoleg uses 400 grit on the left and 600 grit on the right side.  Polishing Press your sample on the course pad (left) to quickly flatten the sample and remove marks left by the wet saw blade. Once the sample has been placed on the course grit pad, check to make sure all the lines are going in the same direction. This allows for a quicker and easier fine polish. Press your sample on the right pad (fine grit) to remove marks left by the course polish.  Cut & Etch We use Dyno-lite digital microscopes to view our welds for cut and etch.  Cut & Etch samples Continuously brush the starting weld with acid until the grain structure appears, both roots, and toes are visible. Making sure there is no debris, deep scratches, flashing or glare present on the weld. For monoleg return leg must be visible. Grain structure needs to be visible so the HAZ is not mistaken for penetration. Samples must be fully etched to definitively say whether a crack is present or not.  Cut & Etch Sample Preparation Poor Sample Preparation Proper Sample Preparation Sample Sample shows displays scratches minimal (if and/or any) polishing scratches and marks; the weld nugget grain nugget grain structure is structure is not visible. clearly visible. Smearing can occur when the abrasive acts as though it is blunt, pushing material across the surface instead of cutting it away. Smearing can be caused by an abrasive with too small a diamond grain size.  Nugget Grain Structure The pattern on the polished surface of the weld nugget May resemble marbling, gravel or grains of salt  Stress Risers Areas where the material is under increased tension or reduced thickness and more likely to crack – Examples: undercut and corners in the material  Cracks Cracks are breaks in the material and are not allowed – Typically found in top corners, near stress risers. Generally run perpendicular to the material edge – May extend through multiple weld features (HAZ width and parent material) – Usually have a jagged and/or branching shape Cracks typically do not: – Follow cleanly along the edge of the weld nugget (This is lack of fusion) – Match grain structure *Cracks are NOT flashing, material overlap or debris Cut & Etch Cut & Etch  Troubleshooting While basic troubleshooting structure can be different depending on the system used, they all have the same basic principles. 1. Problem Identification 2. Establish a Theory of cause 3. Establish a Plan of action 4. Implement the Plan 5. Verify Full Functionality 6. Document Findings, Actions, and Outcomes Problem Identification Find the initial “problem” detected which is likely a symptom of the root cause: When did the problem start showing up? What has changed? Was there a crash or equipment damage, before the problem? Was there a coil change? Are you loading the part into the gage correctly? Problem Identification If you are not the primary operator, what has been done already? Verify that those corrections were performed properly.  Probable Cause Establish a theory of probable cause: Document the list of possible causes and categorize it from highest to lowest probability. Example: hole are not pinning on the gage What does your part geometry look like? Is it nominal? Are the surfaces of the part flat? Especially areas of concern, and datums. Does the die actually need to be shimmed? Establish a plan of action Based on the list of probable causes, create an action plan. Determine if different personnel/tools are needed and are available to help fix the problem. Example: While you are examining the equipment you determine that a die has a stock guide issue you may need a hilo to take the die to the tool room to correct the issue.  Implement the Plan Its go time! It is critical to make only one change at a time, testing the results. Making more than one change at a time may cause unexpected results, causing you to make incorrect assumptions about an adjustment made, more time back tracking, and unnecessarily making additional adjustments. If an unexpected result occurs, don’t be afraid to walk back an adjustment. Verify Full Functionality Once the initial problem is solved, all aspects of the equipment operation need to be tested to validate that no other new or different problems were introduced during troubleshooting. If a new problem was introduced, the new problem will need to be reviewed first before making the decision to reverse work that was already completed. Example: If my part height is off and I come up on my last pass to fix that and it makes the sweep go out of tolerance and creates ripples I may need a different solution to the problem. Document your findings Creating an accessible knowledge base is extremely important. Document your findings on a personal level, notebook computer whatever you have. If you are troubleshooting for someone else or working with another operator on a machine you are running communicate with them what you are doing and why. Building your fellow operator's skills is one of the biggest parts of being a rollform tech 3. GD&T Gage Applications GD&T Gage Applications To apply GD&T to troubleshooting first you must carefully analyze the drawing with GD&T annotations to identify the specific geometric tolerances and datum references that might be causing the issue, then use appropriate measuring tools to verify if the part is failing to meet those tolerances, allowing you to pinpoint the root cause of the problem. This is especially useful when dealing with assembly issues where multiple parts need to precisely align with each other based on defined datums. GD&T Gage Applications Pull up your print! Interpret the drawing Understand the critical features and their associated GD&T symbols on the drawing Identify the datums and how they are referenced in the feature control frames Pay attention to the tolerance values and their corresponding geometric controls (flatness, parallelism, perpendicularity ect.) Isolate the problem area Examine the failed assembly or component to determine which features are not meeting the required tolerance. Example: B datum or 4way that is to big causes your entire part to shift one way or another in the fixture. Analyze which specific GD&T controls might be causing the issue based on the observed malfunction. Example: part is inconsistent in the gage after multiple adjustments flatness where the part nets may be your issue. Use appropriate Measuring tools Utilize measuring equipment like CMM (coordinate measuring machines) escalate to quality if you think there is a problem with the gage. Calipers, Dial indicator, micrometers to verify minor problems. Example: the part has twist upon inspection of the part you find one leg that is too short creating uneven pressure at your last pass and twist. Verify tolerances against Drawing Measure the critical features of the suspect part and compare the measurements to the tolerances specified in the GD&T annotations. Check for any deviations from the required geometric controls Example: if a surface is not flat enough, or a hole is not perpendicular to a datum.  Identify root cause Consider factors like equipment wear, material variations or improper machining techniques that could contribute to the problem. Example: the part has twist upon inspection of the part you find one leg that is too short creating uneven pressure at your last pass and twist. The root of the problem could be that your lead mandrel on one side of the part is worn out causing your height difference and twist in the final part. GD&T Gage Applications GD&T Gage Applications GD&T Gage Applications GD&T Gage Applications Review and Summary Review and Summary Review and Summary  Review and Summary When using the alignment rolls to calculate what the top mill face spacer needs to be, it is extremely important that the top and bottom shafts are ___________. parallel What is the final step in the raft alignment process? Complete a mill face line up chart and turn it in to proper person Mill face spacers need to contain what two pieces of information? Station number and which shaft Any Questions?