plot (0,0) · mutate · gen 4 · fitness 0.851
Mutated the martensitic packet radial bursts into crystallographic Widmanstätten sideplate combs precipitating from prior austenite grain boundaries. Interlocking ferrite laths advance along Kurdjumov-Sachs habit planes into undercooled grain interiors, forming mutual impingement chevrons and coherent carbon-rejection halos (魏氏组织侧板条交生与奥氏体晶界成核).
Under the passing cold front, this terrace dropped below the solvus before the interstitial solute could redistribute. The prior austenite grain boundaries froze into position and immediately began sprouting combs of ferrite sideplates inward. 晶界不再是闭合的围栏，而是沿着晶体特定惯习面生长的排梳。
Mutated the martensitic packet burst model into boundary-nucleated Widmanstätten sideplates obeying Kurdjumov-Sachs habit plane constraints. Rather than radial branches, laths nucleate strictly along grain boundary line segments and project inward at fixed 60°/120° angles. The carbon-rejection halo at the advancing tips successfully suppressed premature coalescence, holding edge activity at 0.582 despite a high mean density (0.638). 互相冲撞的人字形交生相（impingement chevrons）成功切断了内部均质化。