Application of Response Surface Methodology for Modeling of Postweld Heat Treatment Process in a Pressure Vessel Steel ASTM A516 Grade 70

<table class="table-group" id="tab2"><tr><td><table class="table"><tr><td class="thead-hr" colspan="8"><hr/></td></tr><tr class="thead"><td align="left" rowspan="2">Parameters</td><td align="center" rowspan="2">Symbols</td><td align="center" rowspan="2">Units</td><td align="center" colspan="5">Levels</td></tr><tr class="thead"><td align="center">−<i>α</i></td><td align="center">−1</td><td align="center">0</td><td align="center">1</td><td align="center"><i>α</i></td></tr><tr><td class="thead-hr" colspan="8"><hr/></td></tr><tr><td align="left">PWHT time</td><td align="center"><span style="width: 14.9631ptpx;"><svg height="11.8174pt" id="M15" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 14.9631 11.8174" width="14.9631pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M748 650H522L515 622L546 617C580 611 587 604 565 575C518 513 469 451 419 393C376 474 349 534 330 580C318 609 325 612 361 618L383 622L392 650H151L144 622C214 616 224 612 257 543L360 327C270 218 187 124 159 95C106 40 92 34 26 28L17 0H252L259 28L236 31C189 37 188 47 209 78C249 136 308 210 377 294L478 79C494 44 487 37 449 32L418 28L409 0H673L680 28C596 34 591 39 554 116L436 361C526 469 574 521 604 553C659 612 669 614 739 622L748 650Z" id="g113-89"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="765" vert-adv-y="765"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,9.88,3.132)"><path d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z" id="g50-50"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="487" vert-adv-y="487"></glyph.data></g></svg></span></td><td align="center">hr</td><td align="center">5</td><td align="center">10</td><td align="center">15</td><td align="center">20</td><td align="center">25</td></tr><tr><td align="left">PWHT temperature</td><td align="center"><span style="width: 14.9631ptpx;"><svg height="11.8174pt" id="M16" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 14.9631 11.8174" width="14.9631pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M748 650H522L515 622L546 617C580 611 587 604 565 575C518 513 469 451 419 393C376 474 349 534 330 580C318 609 325 612 361 618L383 622L392 650H151L144 622C214 616 224 612 257 543L360 327C270 218 187 124 159 95C106 40 92 34 26 28L17 0H252L259 28L236 31C189 37 188 47 209 78C249 136 308 210 377 294L478 79C494 44 487 37 449 32L418 28L409 0H673L680 28C596 34 591 39 554 116L436 361C526 469 574 521 604 553C659 612 669 614 739 622L748 650Z" id="g113-89"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="765" vert-adv-y="765"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,9.88,3.132)"><path d="M414 144C384 79 371 75 317 75H135L276 221C367 316 408 376 408 465C408 570 327 635 237 635C179 635 131 609 100 575L42 494L67 471C94 510 138 565 205 565C277 565 321 517 321 435C321 348 258 270 195 195C146 137 88 81 33 26V0H411C423 44 433 88 446 135L414 144Z" id="g50-51"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="487" vert-adv-y="487"></glyph.data></g></svg></span></td><td align="center">
                  °C</td><td align="center">470</td><td align="center">520</td><td align="center">570</td><td align="center">620</td><td align="center">670</td></tr><tr class="table-tr"><td colspan="8"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

Experimental factors for response surface methodology.

The Scientific World Journal

tab2

Table 2

Table 2: Application of Response Surface Methodology for Modeling of Postweld Heat Treatment Process in a Pressure Vessel Steel ASTM A516 Grade 70 